 How Developers Create Value by Finding the Highest and Best Use of Land
Making a profit that reflects the considerable risks involved in real estate development is challenging. So how do developers maximize their return on investment? Developers create value by identifying a property's highest and best use and then taking the financial risk necessary to transform that vision into reality. Highest and best use is a real estate term that refers to the most profitable and legally permissible use of a property. In other words, what use of the land will generate the greatest value while complying with zoning regulations and meeting market demand? For example, a single-family home on a large lot may have a certain value as a residence. However, if zoning permits townhouses or multifamily housing, the land may have substantially greater value as a redevelopment opportunity. The difference between those values represents the potential that developers seek to unlock. Zoning Zoning plays a critical role in this process. Local zoning regulations determine what can be built on a property, including density, height, setbacks, parking requirements, and allowable uses. Even small zoning changes can dramatically impact a property's development potential and value. The recently adopted MBTA Communities zoning changes have increased development opportunities in many Massachusetts communities. Cities and towns including Arlington, Belmont, Cambridge, Somerville, and Watertown have been evaluating how to accommodate additional housing through zoning reform. As a result, some properties that were once limited to lower density uses may now support more housing units, creating new opportunities for redevelopment. However, identifying development potential is only the first step. Developers must determine whether a project will generate an adequate return on investment. A site may allow additional housing under zoning, but that does not necessarily mean a project will be financially viable. The projected sale price or rental income must be high enough to allow for a profit after acquisition, architectural, engineering, legal fees, permitting, construction, insurance, interest, taxes, brokerage and other costs. Adding Value The goal is to create more value than the total cost of acquiring and developing the property. The profit is not simply a reward for building something new. It compensates the developer for taking substantial financial risk, investing capital, and navigating a lengthy and uncertain development process. Not every project succeeds. Construction costs can increase unexpectedly. Interest rates can rise. Housing markets can soften. Permits can take longer than anticipated. Community opposition can require costly redesigns or delay approvals. In fact, some proposed developments generate significant neighborhood opposition because residents believe the project is too large or out of scale with its surroundings. Public hearings, design revisions, and permitting challenges can add both time and expense to a project. Successful developers understand that balancing economic returns with neighborhood compatibility is often critical to obtaining approvals. Also, developers need to keep in mind that zoning codes can change over time. For example, due to considerable resident feedback, Cambridge is considering height, density, and setback revisions to the recently enacted Multifamily Zoning Ordinance. Our Development Services As experienced real estate agents working on development projects in Arlington, Belmont, Cambridge, Somerville and surrounding areas, we frequently help developers evaluate development potential. For property owners, understanding a property's development potential can be extremely important. A property's value may be based not only on the existing building, but also on the future opportunities that the land provides under current zoning.
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 Working Paper, author: Suzanne P. Blier, Harvard University Summary of essay findings: Aziz Sunderji’s “The Great Housing Debate” usefully maps the major arguments over housing supply, zoning, land, demand, and affordability through three broad approaches: 1) market realist approaches (legal capacity does not guarantee feasible or affordable construction); 2) conditional-supply approaches (additional housing helps, but its effects depend on scale, time, location, and complementary policies); and 3) supply-side approaches: restrictive regulation is the principal constraint, and liberalization is the main route to more housing and lower price pressure. Its framework is incomplete for a built-out city such as Cambridge. Because much of Cambridge’s redevelopment occurs on occupied parcels and in projects below the inclusionary-housing threshold, gross unit production conceals the loss of older, naturally more affordable homes, tenant displacement, expensive replacement housing, and environmental costs. The central Cambridge question is therefore not simply whether upzoning produces more units, but what kinds of units it produces, what they replace, who can afford them, and whether the net result advances affordability and inclusion. Key takeaways: • Cambridge aligns most strongly with Group 1, “Market Realist Approaches”: exceptionally expensive land, acquisition and construction costs, and developer choices determine what is actually built. Its resemblance to Group 2, “Supply Works - but Under Conditions,” remains limited and unproven. • Gross permit and unit counts are inadequate measures of success. Cambridge should report net units and bedrooms, demolitions, prior and replacement rents, tenant displacement, inclusionary production, and infrastructure and environmental effects. • Sunderji gives too little attention to preservation of existing, less expensive housing and to the environmental and livability consequences of demolition and redevelopment; both belong near the center of the analysis. • Cambridge housing demand is intensified by Harvard, MIT, other area institutions, high-paid biotechnology and information-technology employment, and wealthier newcomers able to outbid less affluent residents. Recent university downsizing may soften one part of demand, but it does not remove these larger structural pressures. • Building more housing improves conditions relative to not building, but the cost of newly constructed housing, affordability subsidies, environmental impacts, preservation of existing housing, and tenant protection remain essential. ____________________________________________ Why are housing costs so high—and why do experts who study the same evidence reach such different conclusions? This question is addressed by Aziz Sunderji in his wide-ranging article “Why Is Housing So Expensive? How Can We Fix It? The Great Debate,” Home Economics, July 2026.[i] His analysis is less a single argument than a map of the modern housing debate. By placing major studies alongside published rebuttals, this analysis shows that the disagreement is not simply between people who believe in supply and people who do not. The real disputes concern what causes scarcity, how strongly zoning affects prices, whether legal capacity becomes financially feasible construction, how quickly new housing reaches lower-income households, and how land values, demolition, finance, inequality, and developer behavior shape the outcome. To allow readers to explore this in greater detail, I have included a summary of the housing cost perspectives in Sunderji’s “The Great Debate” in the appendix, reorganized to feature first the most balanced of the approaches presented in this study into three broad approaches (top image and below, Plate 1 at bottom). The most balanced synthesis is that new housing improves conditions relative to not building at all, but subsidies, preservation, and tenant protection remain essential. Group 1, Market Realist Approaches, argues that legal permission to build does not guarantee that housing will be built quickly, affordably, or at all. Demand, land values, construction costs, demolition, financing, inequality, and developer timing may matter as much as zoning. The central disagreement surrounding this approach is whether land, demand, costs, and developer behavior are the primary limits on housing production, or complications that make meaningful zoning reform even more necessary.  Group 2, Supply Works—but Under Conditions, accepts that new housing generally relieves pressure, while emphasizing that the benefits vary by place, market segment, and time and cannot substitute for assistance to very-low-income households. The central disagreement is mainly about magnitude, distribution, and speed—not whether supply has any effect.  Group 3, Supply-Side Approaches, argues that strong demand becomes high prices chiefly when zoning and approval rules prevent the housing stock from expanding. Taken together, these writers contend that high housing costs arise when regulation prevents construction from keeping pace with demand, and that broader development rights would expand supply, widen access to prosperous places, and ease upward pressure on prices. Critics answer that legal reform alone does not guarantee affordability.  Which of these approaches best explains housing costs in Cambridge? The city provides a strong test case as to whether broad upzoning can create meaningful new supply in a city where land is exceptionally expensive, nearly every parcel is already occupied, and redevelopment often requires demolition. Cambridge is already an exceptionally compact and densely developed city. It occupies only about 6.4 square miles of land and, using 2020 Census figures, ranks as the fifth-densest incorporated U.S. city with more than 100,000 residents, at approximately 18,500 residents per square mile.[ii] The February 2025 Multi-Family Housing (MFH) citywide upzoning ordinance removed minimum lot sizes, density limits, residential unit limits, and residential floor-area limits across much of the city, while making multifamily housing broadly permissible. The ordinance also allowed new buildings or renovated structures to extend to five feet from the property line at the sides and rear, extended what could count as open space to porches, balconies, and rooftops. The theory behind Cambridge’s MFH upzoning is essentially the supply-side one: more legal capacity should produce more homes, ease competition for existing units, and generate additional inclusionary housing.[iii] This raises a broader planning question. Cambridge formally identifies Envision Cambridge as its citywide comprehensive plan and organizes its goals under six broad areas: climate and the environment, housing, the economy, mobility, urban form, and community wellbeing.[iv] These goals are not always mutually reinforcing. In some locations, increased housing production may conflict with objectives involving affordability, historic and neighborhood character, tree canopy, climate resilience, transportation capacity, commercial vitality, and residents’ quality of life. Yet the MFH ordinance greatly expanded as-of-right development capacity citywide without establishing a clear neighborhood-scale or parcel-level process for weighing these competing objectives. In that sense, the reform shifts important decisions away from comprehensive, neighborhood- and site-sensitive planning and toward market forces and broadly granted development entitlements. Yet Cambridge also illustrates why the “limits of upzoning” literature cannot be treated as peripheral. This is not Auckland expanding across large areas of underused land. Much of Cambridge’s new capacity sits beneath existing houses, two-family homes, triple-deckers, and small apartment buildings. To use that capacity, a developer may first have to pay a redevelopment price for an already valuable property, remove functioning housing, relocate tenants, and then finance substantially more expensive infill construction. Cambridge therefore needs to distinguish legal capacity from feasible capacity and gross production from net production. A twelve-unit building replacing three existing apartments produces nine net new homes, not twelve—and the affordability calculation changes again if the demolished apartments were relatively inexpensive, family-sized, or occupied by long-term tenants. Cambridge’s highly differentiated housing market also complicates the supply-side moving-chain theory. The city’s 2025 housing-stock data identify only 3,798 single-family homes among 58,966 total housing units—a mere 6.4 percent of the housing stock.[v] These properties constitute a scarce and highly sought market, particularly when they include historic architecture, gardens, quiet streets, and larger family-sized interiors. Newly constructed apartments and condominiums may therefore be imperfect substitutes for the homes sought by affluent buyers who specifically value detached or historic Cambridge houses. New multifamily construction can still create useful moving chains within the apartment and condominium markets, but it may do relatively little to loosen demand for this increasingly rare category. The strength of a moving chain depends not simply on the number of new units created, but on whether households regard the new and existing homes as genuine substitutes. Cambridge’s upzoning may also be changing who competes for its limited supply of land. Properties are increasingly attractive not only to prospective residents but also to developers and investors based outside the city—and, in some documented cases, outside Massachusetts or the United States—who see newly expanded development rights as a financial opportunity. This additional investor demand can raise acquisition prices and redevelopment expectations even before new housing is built. It also places local homebuyers, small property owners, and affordable housing developers in competition with purchasers who have greater access to capital and who evaluate a property primarily according to its redevelopment potential. The relevant question is whether the added development value is captured principally through speculative acquisition and high-end redevelopment rather than through housing that advances Cambridge’s affordability goals. Sunderji’s overview article, with its discussion of supply, moving chains, and nearby rents, also gives too little attention to other lines of research asking whether upzoning changes the social composition of neighborhoods even when it increases housing production. A 2025 study of New York neighborhood rezonings found that upzoned areas added housing but also became, over time, whiter, more highly educated, and more affluent, with rising housing prices—evidence that additional supply and gentrification can occur simultaneously.[vi] Recent Urban Institute work likewise cautions that upzoning should be paired with affordable housing and anti-displacement measures and notes evidence that added supply may increase the out-migration of low- and moderate-income households unless they have access to subsidized housing.[vii] The omission of existing, naturally more affordable housing is even more consequential for Cambridge. Older housing is not necessarily affordable in an absolute sense, but it is often less expensive than newly constructed housing because its original development costs have long been absorbed and because it may lack the amenities and finishes commanded by the newest buildings. It may also contain larger family apartments, informal arrangements, or long-term tenants paying below current asking rents. Demolishing such housing can remove affordability that does not appear in the city’s official count of income-restricted units. Preservation research generally finds that retaining existing affordable housing prevents displacement and is often less costly than replacing it through new construction. Cambridge itself recognizes acquisition, rehabilitation, adaptive reuse, and preservation as core affordable-housing strategies, and its Affordable Housing Trust has financed both creation and preservation.[viii] This does not mean Cambridge should preserve every existing building or reject added supply. Preserving every existing building could also prevent appropriate additions to the housing stock, and some redevelopment produces a substantial net gain. The better question is what each project replaces and what it adds. A parking lot converted to fifty apartments is fundamentally different from three occupied, moderately priced family apartments replaced by ten luxury units and two inclusionary units. Both may count as “new housing,” but their effects on supply, affordability, displacement, household capacity, and neighborhood composition are not equivalent. Cambridge’s inclusionary requirement partly addresses this problem: projects of ten or more units must devote 20 percent of residential floor area to affordable housing. But the ten-unit threshold may also discourage smaller projects from crossing the ten-unit inclusionary-housing threshold, particularly where no added development entitlement compensates for it. Cambridge thus combines an unusually permissive physical zoning envelope with a substantial affordability charge and relatively weak preservation protections for unrestricted but lower-cost existing homes.[ix] The emerging project pipeline reinforces this concern. The Cambridge Redevelopment Tracker, a crowdsourced inventory created by the office of City Councillor Zusy, identifies 99 active or potential projects since passage of the Multifamily Housing Ordinance. The tracker is a continuously updated, crowdsourced inventory rather than an official city database. Its entries draw on public records, permit filings, property information, and community reports; Councillor Zusy’s office invites corrections and revises entries when errors are identified. The figures should therefore be read as a transparent, dated snapshot of the redevelopment pipeline, not as a final or infallible accounting.[x] Its published project-size categories currently account for 98 of those projects and categorize them by anticipated net change. Seventeen create no net new units, although they may replace existing homes with larger structures; 34 add one to three new units; and 33 add four to nine new units. No project adds 10 to 19 new units, while two add 20 to 24 new units and 12 add at least 25 new units. Thus, 84 of the 98 projects currently classified by size—approximately 86 percent—produce fewer than ten net new units or none at all. Only 14 projects add ten or more new units, although 12 of those are substantially larger projects. These figures show that the redevelopment pipeline is dominated numerically by small changes, often involving demolition or replacement on already developed residential sites, even though a comparatively small number of large projects may ultimately account for much of the total unit production. Because Cambridge applies its inclusionary requirement according to the size and residential floor area of a qualifying project, rather than simply its net-unit increase, the tracker’s net-change categories do not by themselves establish how many affordable units are required. The projects are also unevenly distributed across Cambridge. We can see this the accompanying map of part of Mid-Cambridge projects (Plate 2) which is based on a visual created by Cambridge landscape architect, Elena Saporta,  Indeed, a substantial share of the tracked redevelopment is concentrated in neighborhoods that have historically contained comparatively less expensive housing but larger residential lots. This pattern suggests that the effects of upzoning—including demolition, construction activity, displacement pressure, tree and open-space loss, and other environmental changes—may fall more heavily on some parts of the city than on others. It also raises questions of environmental equity, particularly where additional impervious surface, reduced tree canopy, heat-island exposure, and flood vulnerability are already concerns. In addition to Mid-Cambridge, with seven tracked redevelopment residential projects, neighborhoods experiencing substantial redevelopment activity include North Cambridge, with 11; Riverside, 14; Strawberry Hill, 14; Neighborhood Nine, particularly its western section, 13; West Cambridge, particularly its western section, 10; and Cambridge Highlands, seven. Together, these neighborhoods contain 76 of the 99 geographically identified projects—approximately 77 percent of the total. By contrast, the more densely developed neighborhoods of East Cambridge, with six projects, Baldwin, with two, and the Port, with two, generally contain smaller parcels that may be less readily redeveloped under the new dimensional rules. All three also contain substantial amounts of income-restricted housing, which may affect both redevelopment patterns and the composition of their housing stock. In short, Cambridge should not evaluate the impact of the 2025 MFH upzoning using only three measures—new permits, new buildings, and new inclusionary units. It should track, parcel by parcel, the homes and bedrooms demolished; prior rents and occupancy; gross and net units created; the size and rent of replacement units; tenant displacement and relocation; the share of proposed projects that gain historical approval, obtain financing, and begin construction; neighborhood changes in income, race, tenure, and family composition; and the experiences of residents whose leases are terminated or who leave the city as redevelopment proceeds. Cambridge should also measure tree-canopy loss, added impervious surface on each property, increased neighborhood flood exposure, heat-island effects, embodied carbon from demolition and reconstruction[xi], and the loss of existing solar investments. These impacts should be considered alongside the possible regional environmental benefits of allowing more people to live near jobs and transit. The city should additionally evaluate whether water, sewer, electrical, waste, school, fire, police, and transit infrastructure can accommodate additional building intensity and residents. Because Cambridge has removed minimum parking requirements, it should track changes in household vehicle ownership and street-parking demand, and whether transit and bicycle infrastructure can absorb the resulting travel needs. The core Cambridge question is therefore not simply whether upzoning “works.” It is: Does the reform create enough economically feasible, net new housing to moderate prices while preserving—or replacing—the existing homes, affordability, and residents most vulnerable to redevelopment? Sunderji’s three broad traditions help frame that question, but the Cambridge case reveals two largely missing dimensions: housing preservation and environmental consequences. Supply, subsidy, and tenant protection are not enough if policy ignores the homes, affordability, environmental assets, and established communities lost through redevelopment. Conclusions: Where Cambridge Fits—and What Sunderji Leaves Out Cambridge fits most clearly within Group 1, “Market Realist Approaches.” It is a nearly fully developed city with exceptionally expensive land, substantial acquisition and demolition costs, high construction and financing costs, and property owners who decide whether and when newly granted development rights will be used. These conditions mean that additional zoning capacity may raise redevelopment value without quickly producing housing that is either abundant or affordable. Cambridge shares only a qualified connection with Group 2, “Supply Works—but Under Conditions.” In theory, additional homes can reduce competition relative to what would have occurred without them. In practice, however, the city has not yet demonstrated that the recent upzoning is bringing housing prices down. As of July 2026, the Cambridge Redevelopment Tracker identifies 99 active or potential projects geographically, while its published project-size categories currently account for 98. Of those 98 projects, 84—approximately 86 percent—create fewer than ten net new units or no new units at all. Because Cambridge determines inclusionary applicability from the size and residential floor area of a qualifying project, these net-change figures do not establish that every small project falls outside the requirement. They do show, however, that the pipeline is dominated numerically by projects involving relatively small net changes. Because the tracker is crowdsourced and the project pipeline is changing, these figures should be treated as a dated snapshot rather than a final accounting. The result may be an enlarged single-family house or one to three high-priced condominiums—often priced above $1 million each—rather than a meaningful increase in moderately priced or income-restricted housing. Cambridge also differs from many of the metropolitan cases in Sunderji’s survey because demand here is unusually concentrated and affluent. Harvard, MIT, and other area colleges and research institutions have long attracted students, faculty, staff, investment, and associated businesses.[xii] Although Harvard, MIT, and some related institutions are currently restraining hiring[xiii] or reducing staffing[xiv], this near-term contraction[xv] does not erase their enduring role in attracting students, employees, investment, laboratories, and associated businesses. The biotechnology and information-technology sectors[xvi] add another large population of highly paid workers, while wealthier newcomers from outside Cambridge can outbid less affluent local residents for a limited stock of homes. In that setting, new market-rate construction may accommodate affluent demand without necessarily preventing the displacement of existing residents. The appropriate test of Cambridge’s policy is therefore not whether some new units appear, but whether the reform produces a substantial net increase in homes that a broader range of residents can afford. That assessment must include what is demolished, whether tenants are displaced, whether projects remain below the inclusionary threshold, what new units cost, how many bedrooms are gained or lost, and which environmental and neighborhood assets disappear in the process. The relevant measure of success is not how much development Cambridge legally permits, but whether redevelopment produces a meaningful net gain in housing that a broader range of residents can afford without sacrificing existing affordability, established communities, and environmental resilience. Appendix:
Overview of the principal authors and approaches addressed in Sunderji Group 1: Market Realist Approaches: Markets, Land, and the Limits of Upzoning The Market Realist Approach holds that permission to build is not the same as actual construction. Whether housing is built—and whether it is affordable—depends not only on zoning, but also on demand, land prices, acquisition and demolition costs, financing, construction expenses, inequality, and developer incentives and timing. This group includes: Patrick Condon: added development rights are capitalized into land prices; cities should capture rezoning gains for permanently affordable housing; Thomas Davidoff and Saku Aura: high prices often reflect scarce land and strong demand; local upzoning may yield modest price reductions; Rebecca Diamond: skilled workers follow high wages, raise rents, and help create amenities that further increase demand; supply determines the severity of the price effect; Others include: Yonah Freemark: Chicago upzoning increased land and condominium values without producing additional housing within the study period; Joseph Gyourko, Christopher Mayer and Todd Sinai: “superstar cities” are scarce desirable goods increasingly bid up by affluent households; Greg Howard and Jack Liebersohn: rents rose as demand shifted toward places where housing is difficult to expand; Schuyler Louie, John Mondragon and Johannes Wieland: income growth, rather than measured supply constraints, best explains differences in housing-price growth. Cameron Murray: landowners control development timing; profitable projects may be withheld while owners wait for higher returns, leaving zoned capacity unused; Anthony Orlando and Christian Redfearn: growing cities exhaust inexpensive land and shift toward more costly infill and tall construction, reducing supply elasticity even without tighter zoning; Vincent Rollet: zoning reform increases redevelopment, but slowly; demolition, fixed costs, and migration diffuse the affordability gains over decades; Michael Storper and Andrés Rodríguez-Pose: high-income growth and inequality drive unaffordability; upzoning may replace older housing and accelerate gentrification; Jessica Trounstine: zoning restricts supply, but its deeper significance lies in its use by affluent white homeowners to preserve exclusion and unequal access to public goods; Raven Molloy, Charles Nathanson and Andrew Paciorek: regulation has a larger effect on property prices than on rents and explains only part of the affordability problem. Their critics are: Albert Saiz; Guren, McKay, Nakamura and Steinsson; Jason Barr; Michael Manville, Michael Lens and Paavo Monkkonen; Shertzer, Twinam and Walsh; Michael Wiebe; Russil Wvong; Ryan Greenaway-McGrevy; Vicki Been, Ingrid Gould Ellen and Katherine O’Regan; Stuart Donovan and Matthew Maltman—answer that demand and costs do not make zoning irrelevant. High demand becomes extreme scarcity when supply cannot respond; modest or short-lived upzonings are poor tests; broad, economically usable reforms have increased construction and moderated rents. The central disagreement is whether land, demand, costs, and developer behavior are the main constraints on housing production, or whether they strengthen the case for broad and economically meaningful zoning reform. Group 2: Supply Works—but Under Conditions The Conditional Supply Approach holds that new housing generally eases market pressure, but its effects vary by location, housing type, market segment, and time. Additional supply can improve affordability, but it cannot replace direct assistance for very-low-income households.Vicki Been, Ingrid Gould Ellen and Katherine O’Regan: the newer evidence supports supply, but supply remains necessary rather than sufficient; Cristina Bratu, Oskari Harjunen and Tuukka Saarimaa: Helsinki moving chains reach lower-income households within a year or two; social housing reaches them more directly; Ryan Greenaway-McGrevy: Auckland’s broad upzoning created economically feasible capacity, substantially increased permits, and lowered rents relative to the estimated counterfactual; Xiaodi Li: New York towers create some amenity demand, but the supply effect dominates and nearby rents decline modestly; Evan Mast, Brian Asquith and Davin Reed: new market-rate buildings reduce nearby rent pressure and initiate moving chains reaching lower-income neighborhoods; Kate Pennington: San Francisco construction lowers nearby rents and reduces displacement and eviction risk; Jenny Schuetz: America has two problems—too few homes and too little income; zoning reform addresses scarcity, while subsidies address poverty. Responses: Anthony Damiano and Chris Frenier respond that effects vary by submarket and may raise rents in lower-priced segments. Damiano further argues that the benefits are too small and too concentrated above the bottom of the market to resolve severe affordability. Cameron Murray and Tim Helm question whether some studies identify supply effects rather than demand-driven construction and dispute the Auckland counterfactual. Clayton Nall argues that empirical evidence alone will not settle a debate shaped by values, fairness, and distrust of development. Greenaway-McGrevy, Stuart Donovan and Matthew Maltman defend the Auckland findings; Been, Ellen and O’Regan argue that critics understate the cumulative evidence that constrained supply worsens affordability. The central disagreement concerns how large the benefits are, who receives them, and how quickly they appear—not whether added supply has any effect at all. The most balanced conclusion is that new housing generally improves conditions compared with not building, but it must be paired with subsidies, preservation, and tenant protections. Group 3: Supply-Side Approaches: Regulation as the Central Constraint The Supply-Side Deregulation Approach holds that strong demand produces especially high housing costs when zoning and approval barriers prevent supply from expanding. Bryan Caplan: regulation manufactures scarcity; extensive deregulation could produce very large price reductions; Peter Ganong and Daniel Shoag: high housing costs have interrupted regional income convergence and increasingly exclude lower-wage workers from prosperous places; Edward Glaeser and Joseph Gyourko: large gaps between housing prices and construction costs indicate barriers to entry—a regulatory or zoning tax; Chang-Tai Hsieh and Enrico Moretti: housing constraints prevent workers from moving to productive cities and impose a national economic cost; Ezra Klein, Derek Thompson and Marc Dunkelman: progressive cities created scarcity through decades of procedural and regulatory barriers; Michael Manville, Michael Lens and Paavo Monkkonen: demand is the motor, but supply determines whether growth produces more homes or higher rents; Edward Pinto and Tobias Peter: legalizing small lots, townhouses, duplexes, and other “light-touch density” would restore less expensive forms of housing and support filtering; Albert Saiz: geography and regulation jointly determine supply elasticity; constrained cities translate demand into prices rather than construction. Responses in Group 3 are the scholars and writers challenging the claim that regulation is the central cause of high housing costs: Cameron Murray: disputes Glaeser and Gyourko’s “zoning tax,” arguing the price-cost gap may reflect land economics rather than regulation; Brendan O’Flaherty: says heterogenous land, indivisible lots, city-specific costs, and measurement error can create the same apparent gap; Raven Molloy: argues regulation explains less of the affordability problem when rents, rather than asset prices, are examined; Nathaniel Baum-Snow: emphasizes depletion of well-located land and the closing of the suburban development frontier; Brian Greaney: re-estimates Hsieh and Moretti’s model and finds the claimed national productivity gains from deregulation largely disappear; Kevin Rinz and John Voorheis: argue that the decline in regional income convergence is driven mainly by top-income divergence, weakening Ganong and Shoag’s broader claim; Thomas Davidoff: argues standard supply-constraint measures are entangled with demand and do not cleanly isolate the effect of regulation; Chandler Lutz and Ben Sand: challenge Saiz’s measure of land unavailability and identify significant measurement error; Michael Storper and Andrés Rodríguez-Pose: argue that inequality and high-income economic growth, not zoning alone, drive unaffordability, and that upzoning may worsen gentrification; Hannah Story Brown: says the “abundance” argument understates corporate interests and the failure of public provision; Sandeep Vaheesan: argues deregulation overlooks market power, profit expectations, land ownership, and the need for public investment. The proponents answer that endogeneity and imperfect measurement do not make regulation harmless. Demand may initially produce political resistance to development, after which regulation deepens the shortage. Critics answer that legal reform alone does not guarantee financing, construction, or affordability. The most balanced conclusion is that regulation is neither the sole cause nor a minor detail. It influences whether demand, land scarcity, and economic growth produce additional homes or still higher prices, but zoning reform must be paired with feasible project economics and direct affordability measures. In summary: These authors broadly argue that restrictive zoning and approval systems convert strong demand into scarcity, higher prices, and exclusion, while deregulation and more flexible housing types allow supply to respond and reduce those pressures. Sources [i] Aziz Sunderji, “Why Is Housing So Expensive? How Can We Fix It? The Great Debate,” Home Economics, July 2026, https://homeeconomics.us/the-great-debate [ii] U.S. Census Bureau, “Cambridge city, Massachusetts,” 2020 Decennial Census: population 118,403; land area 6.4 square miles, https://data.census.gov/profile/Cambridge_city%2C_Middlesex_County%2C_Massachusetts?g=060XX00US2501711000 [iii] City of Cambridge Community Development Department, “Zoning for Multifamily Housing,” https://www.cambridgema.gov/cdd/projects/zoning/multifamilyhousing [iv] City of Cambridge Community Development Department, “Envision Cambridge,” roadmap to 2030 and citywide plan organized around six planning topics: Climate and Environment, Housing, Economy, Mobility, Urban Form, and Community Wellbeing, https://www.cambridgema.gov/envision [v] City of Cambridge Community Development Department, “Housing Stock and Residential Properties by Neighborhood: 2025,” Cambridge Open Data Portal, https://data.cambridgema.gov/Housing/Housing-Stock-and-Residential-Properties-by-Neighb/wiba-69ua/about_data [vi] Kim et al., “Upzoning and Gentrification: Heterogeneous Impacts of Neighbourhood-Level Upzoning in New York City,” Urban Studies (published online December 2024), https://doi.org/10.1177/00420980241298199 [vii] Urban Institute, “How Upzoning Affects Housing Supply: Evidence and Implications for Designing Zoning Reform That Works,” June 1, 2026, https://housingmatters.urban.org/how-upzoning-affects-housing-supply [viii] Joint Center for Housing Studies of Harvard University, “Proactive Preservation of Unsubsidized Affordable Housing: Emerging Practices,” https://www.jchs.harvard.edu/research-areas/working-papers/proactive-preservation-unsubsidized-affordable-housing-emerging [ix] City of Cambridge Community Development Department, “Inclusionary Housing,” https://www.cambridgema.gov/cdd/housing/inclusionaryhousing [x] Councillor Zusy’s Office, “Cambridge Redevelopment Tracker,” accessed July 2026. Crowdsourced inventory of active and potential Cambridge redevelopments identified since passage of the Multifamily Housing Ordinance. https://cambridge-redev-tracker.pages.dev/ [xi] Restore Oregon, “Understanding the Carbon Cost of Demolition,” April 12, 2021, https://restoreoregon.org/2021/04/12/understanding-the-carbon-cost-of-demolition/ [xii] City of Cambridge Community Development Department, “Economic Success Spurs Expanded Budget,” 2024, https://www.cambridgema.gov/digital/stories/2024/cityviewsummer2024/economicsuccessspursexpandedbudget [xiii] Massachusetts Institute of Technology, “Hiring Freeze for Non-Essential Positions,” February 14, 2025, https://orgchart.mit.edu/letters/hiring-freeze-non-essential-positions [xiv] Harvard University, “Financial Stewardship Update,” July 14, 2025, https://www.harvard.edu/president/news/2025/financial-stewardship-update/ [xv] Harvard Faculty of Arts and Sciences, “FAS Workforce Planning: A First Step,” July 14, 2026, https://www.fas.harvard.edu/news/2026/07/fas-workforce-planning-first-step [xvi] City of Cambridge Community Development Department, “Top 25 Employers,” updated annually, https://www.cambridgema.gov/cdd/factsandmaps/economicdata/top25employers  . A new kind of battle may be taking shape on Normandy Avenue and South Normandy Avenue—not over a single proposed building, but over the cumulative transformation of an entire neighborhood. Residents report that developers have acquired, or may be in the process of acquiring, properties throughout the area. From the bottom of Normandy and South Normandy and continuing up the hill, the pattern is becoming difficult to ignore. On some stretches, residents believe that as many as one in every two or three properties may now be connected to prospective redevelopment. The concern is not simply that individual homes will be replaced. It is that numerous demolitions, excavations, and major construction projects could occur at roughly the same time, turning a residential neighborhood into an extended construction zone. The Properties Residents Are Watching. These properties are identified by neighborhood residents and include:  87-101 Blanchard Rd. in Cambridge Highlands Under Construction :
Recent Sales
For Sale
Additional examples.
Not every address on this list is at the same stage. Some properties may have been sold, some may be under agreement, some may have been acquired by an LLC or developer, and others may only be the subject of neighborhood reports or preliminary plans. Those distinctions matter and should be verified through the Cambridge property database, Registry of Deeds, building permits, demolition applications, and formal planning documents. But even before every detail is confirmed, the concentration of potentially affected properties raises an important question: What happens when development is reviewed one parcel at a time, while its effects are experienced by an entire neighborhood? More Than a Series of Individual ProjectsViewed separately, each property can be treated as an individual real-estate transaction, zoning matter, or building permit. Viewed together, however, these sites raise much larger questions about infrastructure, environmental conditions, public safety, and the capacity of a neighborhood to absorb rapid and concentrated redevelopment. What will happen to parking and traffic when several construction crews, trucks, dumpsters, and pieces of heavy equipment arrive at approximately the same time? How will the neighborhood’s already limited streets accommodate deliveries, excavation vehicles, contractors, construction staging, and displaced resident parking? What will happen to the area’s water and sewer systems? Normandy and South Normandy are in an area where residents report a high water table and existing basement flooding. When previously open or permeable land is excavated, paved, or built upon—with setbacks potentially as narrow as five feet—where will stormwater go? Water does not disappear simply because a zoning ordinance permits greater building coverage. It may instead be redirected into neighboring yards, foundations, and basements. What Happens to the Houses Next Door? The stability of the soil and the foundations of nearby homes also deserves serious attention. Excavation, demolition, dewatering, pile driving, and the movement of heavy equipment can affect surrounding structures, particularly older houses that were not built with intensive construction occurring only a few feet away. Who will document the condition of neighboring homes before construction begins? Who will pay if foundations crack, retaining walls shift, plaster separates, or water begins entering basements that were previously dry? Residents should not be expected to prove after the fact that a construction project caused damage when no independent record of preconstruction conditions was created. Trees, Pollution, and Demolition DebrisThere are environmental concerns as well. How many mature trees will be removed? What will the combined loss of tree canopy mean for summer heat, stormwater absorption, wildlife habitat, air quality, and neighborhood character? How much demolition debris will be generated, and where will it go? Have older structures been properly inspected for asbestos, lead, and other hazardous materials before demolition? What protections will be in place for nearby residents while buildings are being taken apart? Each project may submit its own engineering documents, traffic plans, environmental reports, and construction-management proposals. But individual project reports may not capture the cumulative effects of several major construction sites operating within a few blocks of one another. Put the Properties on a MapA neighborhood lot map could make the scale of the change visible. If every property sold to a developer, held by a development-related LLC, proposed for demolition, or connected to a substantial building project were highlighted in yellow, the result might be startling. Who Evaluates the Cumulative Impact? That leads to the central question: Is any city or state agency responsible for protecting a neighborhood from the cumulative effects of development? Cambridge generally reviews construction and redevelopment property by property. But neighborhoods experience development collectively. Residents live with the combined traffic, noise, dust, flooding, tree loss, infrastructure demands, construction vehicles, and structural risks. A permitting system that examines every parcel in isolation may fail to recognize when the concentration and timing of redevelopment have crossed an important threshold. The issue is not whether housing should ever be built, or whether individual property owners should be prevented from making reasonable changes. The issue is whether rapid, simultaneous redevelopment can occur without a serious neighborhood-wide assessment of infrastructure, groundwater, soil, trees, traffic, pollution, and construction impacts. What the City Should Do Now: Before widespread excavation and demolition begin across Normandy and South Normandy, the city should prepare a cumulative-impact assessment for the area. At a minimum, we should:
Residents should not have to wait until their basements flood, their walls crack, their trees disappear, or their streets become impassable to demonstrate that these projects were connected. The new battle of Normandy is not simply about one building, one sale, or one zoning decision. It is about whether a neighborhood can be transformed parcel by parcel without anyone taking responsibility for what happens to the neighborhood as a whole.  Takeaway:
Curb-cut applications matter in providing information on the impacts of our city's 2025 Multi-Family Upzoning. 202 Garden Street near Fresh Pond, reveals some of the financial issues behind such decisions. This removes one of the more affordable city homes and replaces it with a three 4-story condos which will be way of of reach of most Cambridge residents - and others. Key Figures
A curb-cut application for “The Residences at 202 Garden” offers an early look at the financial model behind a growing number of Cambridge redevelopment projects. A compact lot purchased for approximately $1.825 million in this Fresh Pond area neighborhoodis proposed to become three narrow, four-story townhouses, each with ground-floor garage parking. The completed residences could have a combined market value of approximately $7.2 million to $7.8 million. After construction, financing, professional services, permitting, site work, and sales expenses, the developer could plausibly earn approximately $650,000 to $1.2 million, with a particularly favorable outcome potentially producing more. Each unit would likely sell for approximately $2.4 million to $2.6 million. A household financing a purchase with a 20 percent down payment could need an annual income of approximately $565,000 to $610,000—more than three times Cambridge's 2023 median family income of $164,600. The curb cut is central to this financial model. It permits each narrow townhouse to be marketed with private garage parking—an amenity that can substantially increase its value. What may appear to be a minor driveway application is therefore an essential part of transforming one small parcel into three multimillion-dollar market-rate residences. From a $1.825 Million Lot to Three Luxury townhouses. The recently filed curb-cut application for 202 Garden Street provides a useful starting point for understanding the economics behind Cambridge’s current redevelopment activity. The proposed project is called “The Residences at 202 Garden.” According to the City of Cambridge notice circulated to neighbors, the developer proposes to construct three four-story townhouses with garage parking. The project would therefore consist of three narrow, vertically organized condominium residences constructed on a single compact lot. The land sold in February 2026 for approximately $1.825 million. The commercial real-estate website Traded described the property as a “by-right development opportunity.” That description is important: its value was based not simply on what occupied the property at the time of sale, but on what a developer believed could be constructed and sold there. How Three Townhouses and Three Garages Could Fit: The lot contains approximately 3,850 square feet of land. Three conventional detached houses would not fit on a property of this size. Instead, the proposal appears to rely on three attached or very closely spaced townhouse units, with most of their living space stacked above ground-floor garages. Each residence would likely include:
Over four levels, that could produce approximately 2,300 to 2,700 gross square feet per residence. The garage, stairways, walls, utility areas, and circulation space would reduce the amount marketed as finished living space. A reasonable preliminary estimate is therefore approximately 1,900 to 2,300 square feet of finished living area per townhouse, together with one enclosed parking space. This would represent an intensive use of a small site. Most of the property’s value would be created not through generous yards or ground-level open space, but by stacking expensive living space vertically. What could the townhouses sell For? The proposed residences would be newly constructed and would each include garage parking—both significant selling points in Cambridge. They would, however, also be narrow, vertically arranged homes with multiple flights of stairs and limited private ground-level outdoor space. Their final value would depend on the quality of the architecture, finishes, natural light, layouts, roof decks, and whether each unit feels like an independent house rather than one section of a tightly packed building. A reasonable preliminary sales range is: Sales scenario: Per townhouse three-unit total More conservative: $2.15 million and $6.45 million Likely middle range: $2.4–$2.6 million and $7.2–$7.8 million Strong luxury market: $2.7 million and $8.1 millionThe most plausible working estimate is approximately $2.4 million to $2.6 million per residence, producing a combined finished market value of roughly $7.2 million to $7.8 million.
Who Could Afford One of these homes? At prices of $2.4 million to $2.6 million, the residences would be affordable only to households with exceptionally high incomes, substantial existing wealth, or both. The following calculation assumes:
Purchase price: 20% down payment and mortgage. Estimated monthly housing cost. Approximate income needed: $2.4 million: $480,000. $1.92 million. $14,100$. 565,000 a year $2.5 million: $500,000. $2 million. $14,700. $588,000 a year $2.6 million: $520,000. $2.08 million. $15,300. $610,000 a year. The monthly estimates include mortgage principal and interest, property taxes before any residential exemption, insurance, and assumed shared-property expenses. They do not include utilities, interior maintenance, repairs, furnishings, or other household debts. Using the common affordability standard that housing should consume no more than approximately 30 percent of gross income, a household would need to earn about $565,000 to $610,000 per year. A lender might approve a somewhat lower-income household if the buyers had minimal debt, excellent credit, considerable financial assets, and large cash reserves. But qualifying for a loan is not the same as being able to carry it comfortably. More Than Three Times Area Median Income: HUD’s FY2026 median family income for the Boston-Cambridge-Quincy metropolitan area is $164,600. The estimated income needed to purchase one of the 202 Garden residences would therefore equal approximately:
For comparison, HUD’s 2026 80-percent income limits are:
The units should therefore not be described simply as “market-rate housing” without explaining what segment of the market they would serve. These would be homes aimed at a narrow upper-income or high-wealth clientele. Income Alone Would Not Be EnoughEven a household earning $600,000 annually would still need approximately half a million dollars in cash for a conventional 20 percent down payment. Closing costs, prepaid taxes, insurance, legal expenses, moving costs, and lender-required reserves could require tens of thousands of dollars more. Likely purchasers might include:
What Would the Project Cost to Build? The difference between the $1.825 million land price and the eventual sales total would not be pure profit. Construction costs in Cambridge are unusually high. This is a constrained urban site requiring three tall residences, three garages, fire separations, structural work, separate heating and cooling systems, high-end kitchens and bathrooms, and extensive utility and site work. A preliminary development budget might look like this: Project expense: Estimated cost Purchase of the land: $1.825 million Building construction: $3.1–$3.8 million Architecture, engineering, surveying, and permits: $350,000–$500,000 Site work, utilities, landscaping, and curb-cut work: $150,000–$300,000 Financing, taxes, insurance, and carrying costs: $350,000–$600,000 Brokerage, marketing, and closing expenses: $350,000–$450,000 Construction contingency: $200,000–$300,000. Likely total project cost$6.3–$7.8 million. The upper end of that range would leave little or no profit unless the homes sold at particularly high prices. A developer moving forward with the project presumably expects to keep expenses nearer the lower or middle portion of the range. A plausible working estimate places 202 Garden Street total costs at approximately $6.6 million to $6.9 million. The Potential Profit: If the townhouses sold for an average of $2.5 million each, total sales would equal approximately $7.5 million. Depending on the final construction and financing costs, that could produce:
These are estimates, not the developer’s disclosed projections. The complete plans, construction contract, financing terms, and eventual sale prices are not yet public. They nevertheless indicate the project’s likely financial scale: one small parcel acquired for $1.825 million could be transformed into three residences with a combined market value approaching or exceeding $7.5 million. Three Large Homes Rather Than More Smaller Units: The project demonstrates how a developer can maximize the market value of a property without maximizing the number of homes created. The available building volume might conceivably be divided into more, smaller condominiums, especially if fewer parking spaces were supplied. Instead, the developer appears to have selected three large luxury townhouses, each with its own garage and entrance. That choice offers several financial advantages:
Cambridge’s Inclusionary Housing Ordinance applies to residential projects creating ten or more new units or more than 10,000 square feet of residential space and requires 20 percent of residential floor area to be affordable. Based on the estimated size of these three residences, the project appears likely to remain below both thresholds. The result could therefore be three market-rate homes with a combined value approaching $8 million, without an inclusionary affordable unit. This is one reason unit counts and floor area matter. A project may add substantial market value while producing only a small number of exceptionally large and expensive homes. What the Project Adds—and What It Does Not: The proposal would add three dwellings to Cambridge’s housing count. It would not, however, create homes affordable to households near the area median income, much less low- or moderate-income residents. The likely purchasers would need incomes exceeding half a million dollars a year, considerable accumulated wealth, or some combination of the two. The project may therefore increase the numerical housing supply while doing little to address the housing needs of the typical Cambridge-area household. This does not mean that the units will find no buyers. Cambridge’s market clearly contains purchasers able to pay these prices. It does mean that the three units should be understood for what they are: extremely high-cost housing aimed at a narrow and affluent segment of the market. Why the Curb Cut Matters: Seen in isolation, a curb-cut application may appear to be a minor administrative request concerning the location of a driveway. At 202 Garden Street, however, the curb cut is integral to the development’s financial strategy. The proposal depends on supplying a private garage for each townhouse. Those garages help turn three narrow, vertically organized units into premium properties potentially worth $2.5 million or more apiece. The curb cut is therefore not incidental. It helps make the project’s high-end sales model possible. It may also affect the sidewalk, on-street parking, pedestrian movement, landscaping, street trees, and the appearance of the streetscape. Cambridge itself notes that curb cuts can significantly affect neighborhood safety and quality of life and must be reviewed in light of the public welfare. This is why curb-cut applications can serve as an early warning system for redevelopment. They may reveal the intended physical design and financial model of a project before construction has fully entered public view. 202 Garden Is Not an Isolated CaseThe discovery of the 202 Garden Street transaction led Cambridge resident Doug Brown to identify several other recent Cambridge property sales on the same commercial real-estate website. The additional properties include:
Not every sale will necessarily result in demolition. Nevertheless, the combination of developer ownership, high acquisition prices, parcel assembly, vacant possession, and development-site marketing makes these important locations to monitor. Together, the properties identified by Brown represent nearly $28 million in real-estate acquisitions before new construction begins. Their completed market value could be many millions of dollars higher. Their potential profits, however, cannot be calculated merely by subtracting the acquisition prices from future sales. Each project will also involve construction, financing, architecture, engineering, permitting, insurance, taxes, and marketing expenses. The next step is to examine each property individually:
Viewed separately, these transactions may look like ordinary private real-estate deals. Viewed together, they may reveal a broader Cambridge pattern of property acquisition, demolition, displacement, parcel assembly, and high-end redevelopment. The questions raised by 202 Garden Street therefore extend far beyond one small lot and one curb-cut application. They concern how Cambridge land is being transformed, how much private value is being created, what kinds of housing are being built, who will be able to afford them, what is being lost in the process, and how often major redevelopment first becomes visible through what appears to be a routine request for a driveway.  A security deposit may seem like a small matter in a city debating zoning, development, and billions of dollars in real estate. But when a landlord or developer holds on to a tenant’s money without explanation, it reveals something larger: how easily longtime residents can become an afterthought when a building changes hands. I lived for six years in a second-floor apartment in a typical Cambridge two-family house. Then, in late February, our landlord informed us that the building was being sold. “The expected closing date will be in April,” he wrote. “Your current lease will remain in effect for its duration. Beyond that you will need to discuss future plans with the buyers.” He said he would speak with the buyers about communicating with the tenants. We never heard from them. The sale went through, and we were left in the dark about what would happen when our leases expired on June 1. We later learned that the new owners had already sold the property to a real estate development company with luxury projects elsewhere in Massachusetts and on the Mediterranean island of Cyprus. No one formally told us that we had to leave. No one explained what was planned for the building. But the message was clear enough. We began scrambling to find new homes. On May 19, a broker representing the newest owners told one of the tenants that our security deposits would be returned soon. We moved out by June 1. Then we waited. One week passed, then another. No checks arrived. I repeatedly called the broker, but he did not answer or return my messages. He seemed always to be away or on vacation. As the thirty-day legal deadline approached, I left another message, pointing out that the owners were now failing to comply with Massachusetts law—and that this was not a good look for a company apparently hoping to expand its presence in Cambridge. Still, there was no response. Nobody likes to feel that they are being ignored or taken advantage of, especially after six years of paying rent and caring for a home. I contacted Suzanne Blier, Cambridge City Councillors Cathie Zusy and Patricia Nolan, and resident Doug Brown, all of whom have raised concerns about Cambridge homes being purchased by investors, emptied of tenants, demolished, and replaced with much more expensive housing. Finally, Councillor Nolan intervened. Because the tenants had never been given the owners’ names or contact information, she sent an email directly to them. On July 13—more than six weeks after I had moved out—I finally received my security deposit. My experience is a small one. I eventually got my money back. But it is also part of a much larger story about who has power in Cambridge’s rapidly changing housing market. When a building is repeatedly sold, the tenants living inside it can become almost invisible. Owners, brokers, investors, and developers communicate with one another, while residents are left uncertain about whether they can remain in their homes, whom they are renting from, or even how to recover money legally owed to them. Cambridge’s new citywide Multifamily Housing zoning was promoted as a way to produce more housing and improve affordability. But increased development rights can also make ordinary homes more attractive to investors seeking high returns. Without strong tenant protections, meaningful affordability requirements, design oversight, and safeguards against unnecessary demolition, the result may be more displacement—not greater housing security. The central question is not simply how many housing units Cambridge can build. It is what kind of city those policies will create, who will be able to remain here, and whether existing residents will be treated as members of a community or merely as obstacles standing between an investor and a profitable redevelopment. What will Cambridge look like in fifty years? The answer will depend not only on how much we build, but on whether the people already living here are respected, protected, and allowed to remain part of the city’s future.  At a glance...
A new California study finds that inclusionary-zoning requirements can reduce housing production when the affordable-housing obligation absorbs too much project revenue. Cambridge should not simply import the study’s estimates, but its central lesson is directly relevant to the city’s current 20 percent rule. • Cambridge requires projects of 10 or more units to devote 20 percent of residential floor area to income-restricted housing. • On many parcels, developers now receive no additional height, floor area, unit allowance, or approval benefit in exchange for that obligation. • With Cambridge’s unusually high land, demolition, construction, and financing costs, a 20 percent requirement can make smaller projects infeasible or encourage developers to stop at nine units. • Demolition means the city must count net new homes—and the existing units, bedrooms, rents, and residents lost—not merely the gross number of units proposed. • A graduated policy—10 percent for smaller projects, rising toward 20 percent for larger projects or those receiving added public value—would better balance production, affordability, and preservation. Bottom line Cambridge should retain inclusionary housing, but modify the present one-size-fits-all rule. A flat, uncompensated 20 percent requirement beginning at 10 units is too blunt for a city where development often requires purchasing and demolishing extremely expensive existing homes. A lower requirement for smaller projects, combined with stronger demolition, replacement, and tenant protections, is more likely to produce both additional housing and meaningful permanent affordability. _______________________ A new working paper on inclusionary zoning should prompt Cambridge to take a fresh look at its own affordable-housing requirements. In Inclusionary Zoning and Housing Supply: Evidence from California’s Palmer Fix, economist Noah Kouchekinia examines local rules requiring private developers to reserve part of a new building for below-market-rate housing. His central finding is straightforward but important: the more costly the inclusionary requirement, the greater the apparent reduction in housing production. Read this June 11, 2026 article: HERE. Kouchekinia estimates that the typical binding California ordinance reduced annual housing permitting by roughly one-third. Less stringent requirements had smaller and statistically uncertain effects, while the largest reductions were associated with the most demanding ordinances. The paper also estimates that inclusionary zoning can raise market rents: households fortunate enough to receive an affordable apartment benefit substantially, while lower-income households that do not receive one may be harmed by the resulting reduction in housing supply. The paper is a working draft, and California is not Cambridge. Its precise estimates should not simply be transferred to Massachusetts. But its central principle is highly relevant: Inclusionary zoning should be evaluated according to its actual financial burden, not simply by whether a city has such a policy. That question has become particularly urgent in Cambridge because the economic rationale underlying the city’s 20 percent requirement has changed. Cambridge’s current requirement: Cambridge requires residential developments creating at least 10 units—or more than 10,000 square feet of residential space—to devote 20 percent of their residential floor area to income-restricted housing. The requirement applies to floor area, not merely to the number of apartments. That distinction matters. A developer cannot substantially dilute the obligation simply by dividing a building into more, smaller apartments. Twenty percent of the residential space must remain affordable. The affordable units created through this program are valuable. They are integrated into privately owned developments and provide permanently restricted homes in a city where ordinary market rents are beyond the reach of many households. Cambridge reported 9,021 income-restricted affordable homes in 2025, out of approximately 58,966 permitted or completed housing units citywide. For the households that obtain these apartments, the benefits can be life-changing. The question is not whether these homes are worthwhile. They plainly are. The question is whether requiring 20 percent at the 10-unit threshold is the most effective and equitable way to produce them under Cambridge’s new zoning system. The original bargain has largely disappeared. Cambridge’s inclusionary program once operated as something resembling an exchange. Developers subject to the requirement could receive a 30 percent increase in permitted floor area and unit count. The city’s earlier program generally produced an effective affordable share closer to 11 or 12 percent after accounting for that bonus. In 2017, Cambridge increased the affordable requirement to 20 percent. But Cambridge subsequently transformed its residential zoning. The 2025 citywide multifamily amendments removed general residential unit-density limits and made multifamily housing permissible throughout nearly the entire city. Cambridge itself has acknowledged that the old density bonus is no longer generally applicable because multifamily residential density is no longer capped citywide. On parcels where six-story market-rate residential construction is already permitted as of right, a project receives no extra stories for providing the required affordable units. It does not receive an additional unit allowance. It does not receive an additional residential floor-area allowance. And it does not receive a special as-of-right process unavailable to an entirely market-rate project. In those circumstances, the 20 percent requirement no longer functions principally as a trade of affordability for added development capacity. It functions as a mandatory cross-subsidy imposed on new housing. What does 20 percent cost? The answer depends on the difference between market rents and the rents produced by the affordable apartments. Suppose, for illustration, that an inclusionary apartment generates 60 percent of the rent of a comparable market-rate apartment. Under a 20 percent floor-area requirement, the building would produce approximately 92 percent of the gross residential revenue of an entirely market-rate building:
If affordable rents equal 70 percent of market rents, the gross reduction is about 6 percent. If they equal 50 percent, it is about 10 percent. These figures may sound manageable until they are considered against the full cost of development. The affordable units do not cost 50 or 60 percent as much to build. They require the same land, foundations, structure, plumbing, utilities, fire protection, elevators, finishes, maintenance and financing as the rest of the building. A loss of 6 to 10 percent of gross revenue can therefore consume a much larger share of the developer’s expected return. On a marginal project, it can be the difference between financing and cancellation. That is precisely the distinction emphasized in Kouchekinia’s paper. Mild requirements may have limited effects, while a requirement consuming a larger share of anticipated revenue can substantially reduce production. Why Cambridge land costs make this especially difficult: Cambridge development rarely begins with inexpensive vacant land. A developer commonly must purchase an existing house, two-family home, triple-decker or small apartment building. The sale price reflects not only the value of the existing structure but also the anticipated value of the redevelopment opportunity. The developer must then pay for design, legal and engineering work, financing, demolition, environmental remediation, construction, insurance and sometimes tenant relocation. The acquisition expense is already exceptionally high before a single net new apartment is created. Cambridge has itself identified land, construction and financing expenses as major impediments to new development. It has also noted that structured parking can cost $100,000 or more per space, illustrating the scale of the fixed expenses that can affect multifamily feasibility. A 20 percent rent restriction does not reduce any of those costs. It reduces the income available to pay them. This burden is particularly difficult for a 10-, 12- or 15-unit project. Smaller developments must absorb many of the same acquisition, professional, demolition and construction expenses as larger projects, but have far fewer apartments across which to distribute them. *The 10-unit cliff Cambridge’s requirement also begins abruptly. A nine-unit project may be entirely market rate. Add one more apartment, and 20 percent of the entire residential floor area becomes subject to affordability requirements. This is not a gradual contribution. It is a cliff. The predictable result is that some owners will stop at nine units, even when the permitted building envelope could accommodate more. Others may keep a project below 10,000 square feet. Some projects may be postponed until market rents rise enough to carry the additional burden. A policy intended to create affordable housing can consequently produce the following outcome:
Reducing the requirement to 10 percent would not eliminate the cliff, but it would make crossing it considerably less punitive. Using the same illustrative rents, a 10 percent requirement would reduce gross project revenue by approximately 3 to 5 percent rather than 6 to 10 percent. That difference can be decisive for a smaller project. Would reducing the requirement eliminate affordable housing? No. But it would create fewer affordable apartments in each project. In a hypothetical 100-unit-equivalent building:
To produce the same number of inclusionary apartments under a 10 percent rule, qualifying construction would need roughly to double. No one should assume that this would happen. A lower requirement would probably make more projects feasible, but construction costs, interest rates, land prices and physical constraints would remain. The most likely result of reducing the requirement would be:
That is the real tradeoff. It should be acknowledged rather than obscured. Demolition changes the equation. Should one choose 10% or 20%? For a small project of 10–19 units that must purchase and demolish existing Cambridge housing, I would generally choose 10%, accompanied by tenant, replacement, and preservation protections. My reasons are:
For a large project on a commercial, institutional, parking, industrial, or substantially underused site, I would be more inclined to retain 20%. Such projects can spread costs across many units, usually produce a much larger net housing gain, and do not necessarily destroy existing homes. Cambridge’s redevelopment pattern adds another complication: many new projects require demolition of existing homes. A proposal to replace a two-family house with 10 apartments does not create 10 net new homes. It creates eight. Cambridge now properly measures housing growth on a net basis, accounting for units removed through demolition or consolidation. But even net unit count does not tell the whole story. An existing two- or three-family property may contain relatively moderate rents, large apartments, family bedrooms, yards, porches and long-established tenants. These homes may not be legally classified as affordable, yet they may cost considerably less than the new market-rate apartments replacing them. A redevelopment project therefore needs to be evaluated in at least three ways:
Under a 20 percent requirement, the rough result might be:
But suppose the 20 percent requirement instead causes the owner to stop at nine units. Cambridge might then receive:
The policy cannot be evaluated by looking only at the percentage printed in the ordinance. We need to know how the requirement changes actual development decisions. Demolition cuts both ways! The destruction of existing homes strengthens the case for a meaningful affordability requirement. Cambridge should not encourage the widespread replacement of existing houses with buildings containing only very expensive apartments. There are sizable environmental costs of demolitions as well. But demolition also strengthens the case against imposing the same uncompensated 20 percent burden on every project. A 100-unit building constructed on a parking lot or underused commercial property is not economically equivalent to a 10-unit building that must first acquire and demolish an expensive, occupied residential property. The larger project spreads land, design, legal, elevator and construction expenses over many more units. It also creates a much greater net increase in housing. One fixed percentage cannot adequately account for these differences. Why we should favor 10 percent for smaller projects: For projects of approximately 10 to 19 units receiving no additional height or development capacity, I would recommend reducing the ordinary inclusionary requirement to 10 percent. The reasons are practical:
One should not, however, recommend a blanket 10 percent rule for every project. Larger developments can generally spread costs more efficiently. Projects built on parking lots, commercial sites or substantially underused land may be better positioned to support a higher requirement. Projects receiving additional height beyond the normal market-rate entitlement are also receiving real public value and can reasonably be asked to return more of that value through affordability. A more effective and smarter Cambridge policy: Cambridge should replace the flat 20 percent rule with a graduated structure. An illustrative framework might be:
Cambridge should also treat the demolition of existing housing separately from the basic inclusionary percentage. Legally restricted affordable units should be replaced one-for-one before the inclusionary obligation is calculated on the additional development. Projects demolishing occupied or demonstrably lower-rent homes should provide meaningful tenant relocation protections. The city should document the number of units, bedrooms, residents and rents being removed—not merely the number of new apartments proposed. Preservation should also be made a realistic alternative. Additions, rear buildings and designs incorporating sound existing structures should not be placed at a disadvantage compared with complete demolition. Who should pay for affordable housing? The deeper problem is that inclusionary zoning asks new housing to finance a broad public good. Affordable housing benefits Cambridge as a whole. It supports economic diversity, local employment, families, schools and the ability of residents to remain in the city. Yet under the current system, much of the cost is placed on:
Existing homeowners, owners of older apartment buildings and commercial property owners benefit from Cambridge’s prosperity and social diversity but do not contribute to inclusionary housing in the same direct way. Cambridge has demonstrated that it can produce affordable housing through public and nonprofit development as well. In 2025, the city reported 9,021 affordable homes, including significant projects supported through the Affordable Housing Trust and Cambridge Housing Authority. A more equitable system would require a reasonable private contribution—perhaps 10 percent for smaller by-right projects—and use public funds, tax policy or genuine additional development rights to produce deeper affordability beyond that level. Cambridge needs new evidence! Cambridge should not defend its present 20 percent rule using assumptions developed under the former zoning system. The city’s earlier feasibility work examined a program in which a density and floor-area bonus helped compensate developers. Cambridge now acknowledges that the density bonus is no longer generally applicable after the removal of citywide multifamily density caps. The city needs a new study evaluating actual Cambridge prototypes under current conditions. That analysis should include:
It should also examine projects that were proposed but never built. Looking only at completed inclusionary developments tells us that those particular projects were feasible. It tells us nothing about the projects that were downsized, delayed or abandoned. The real choice: The choice is not simply between “20 percent affordable housing” and “10 percent affordable housing.” It is between: a higher requirement imposed on fewer completed projects and a lower requirement potentially applied to a larger number of projects. Nor should Cambridge treat every demolition followed by a larger building as an unqualified housing success. The city must count what is lost as well as what is built. Kouchekinia’s California study does not settle what Cambridge’s percentage should be. But it gives Cambridge a reason to stop treating the inclusionary requirement as costless. A policy cannot provide a large subsidy to some residents without that subsidy being paid for somewhere. On smaller projects built on extraordinarily expensive Cambridge land—especially those requiring the demolition of existing homes—a flat, uncompensated 20 percent requirement beginning at 10 units is too crude. A 10 percent requirement for smaller projects, rising gradually with project scale and with the value of additional development rights, would better balance three goals Cambridge too often treats as interchangeable:
All three matter. A carefully calibrated policy can advance them together. A single rigid percentage cannot. When Five Feet Isn’t Enough: How Cambridge Zoning Changes Put Trees and Flood Resilience at Risk7/20/2026  An important short video posted on Facebook and other Social Media in mid-July, 2026 addresses the serious flood risks posed by the city's Multi-Family Housing Upzoning.
Here is the link: https://www.facebook.com/reel/1753385475651432 Below is the transcript. Hi, fellow Cambridge residents. I’m Karen. I’m here in front of 18 Thingvalla [in Strawberry Hill]. As you can see, this whole plot is clear-cut, with the exception of a few trees remaining in the back that don’t look so healthy. This fence line over here used to be chock-full of mature trees, but has been stripped by the developers. This is happening all over our city because of the new five-foot setbacks that are now allowed due to multi-family housing zoning changes. Within five feet, you can have a pathway which takes up three and a half feet, and then you’re simply left with one and a half feet of space. It’s not enough for any trees to grow, and barely even any shrubs or plants to grow. By filling up our lots, we’re taking away our permeable space. Permeable space and mature trees are what make our stormwater system work. They are the first line of defense to prevent flooding in low-lying areas of the city, like The Port and Alewife. My background is actually in mechanical engineering, and I’ve run a utility’s wastewater plant, so I have a background in stormwater management. And if we get rid of this critical city infrastructure—our mature trees and our green open space—we’re now sending a ton more water off to the city, which will result in more frequent and more severe flooding in low-lying areas. This water isn’t just water. It can be stormwater mixed with sewage, so it’s a hazard and a safety risk as well. We need to ask our City Council members to protect our residents and amend multi-family housing zoning and our tree protection ordinance so that we can have the climate resiliency we deserve and the safety our community needs.  Cambridge is facing one of the largest infrastructure investments in its history—not for a new school, library, or transit line, but to address a problem buried beneath our streets.
More than half of Cambridge's sewer system—approximately 55%—still consists of combined sewers that carry both sanitary sewage and stormwater through the same pipes. This is a legacy of the city's nineteenth-century infrastructure, when a single pipe system made practical sense. Today, however, that aging system poses growing environmental and financial challenges. Under normal weather conditions, wastewater and stormwater are conveyed to regional treatment plants. During heavy rain or snowmelt, however, the volume of water entering the combined system can exceed its capacity. To prevent sewage from backing up into homes, businesses, and streets, excess flow is diverted through Combined Sewer Overflow (CSO) outfalls into the Charles River, Alewife Brook, and the Mystic River. These overflow events release diluted but untreated sewage into local waterways. Cambridge has spent decades working to solve this problem. Separation of the combined sewer system began in the 1930s, and over the past fifty years the City has invested heavily in separating stormwater from sanitary sewer lines. Yet many neighborhoods still rely on the original combined system. The scale of the remaining work is enormous. The City's Draft CSO Control Plan estimates that approximately $1.3 billion will be required to dramatically reduce combined sewer overflows and eliminate them during a typical 2050 rainfall year, even as climate change is expected to bring more frequent and intense storms. The proposal represents one of the most significant public infrastructure investments Cambridge has ever undertaken. No one disputes that this work is necessary. Clean rivers, healthy neighborhoods, and resilient infrastructure benefit everyone. The question is who should pay for the additional burden created by new development. The City's engineering work is based on years of careful research and planning. However, much of that planning necessarily preceded Cambridge's recent citywide upzoning, which now permits substantially larger buildings, additional dwelling units, and greater residential density across much of the city. More housing means more impervious surfaces, more roof runoff, more paved areas, and more wastewater entering an already stressed system. Although modern stormwater regulations help reduce runoff from individual sites, increased development still places additional demands on public infrastructure that must ultimately be financed, maintained, and expanded. This raises an important policy question. If new development increases the need for billion-dollar public infrastructure investments, should existing Cambridge residents and businesses bear those costs alone through taxes and utility fees? Or should the developers and investors who benefit financially from expanded zoning contribute a greater share toward the infrastructure required to support that growth? Cities routinely require developers to help fund roads, water mains, schools, parks, and utilities through impact fees, mitigation payments, or negotiated public benefits. Yet Cambridge's recent upzoning largely grants additional development rights without requiring proportional contributions toward many of the long-term infrastructure costs that accompany increased density. Combined sewer overflows illustrate why infrastructure planning cannot be separated from land-use planning. Every new building depends not only on zoning approvals but also on pipes beneath the streets, treatment plants downstream, drainage systems, electrical capacity, urban trees that absorb stormwater, and public investments that residents have funded over generations. As Cambridge continues to grow, it should ask a straightforward question: When growth creates new infrastructure costs, who should pay? The answer matters because the bill is not theoretical. It is approximately $1.3 billion—and rising. Growth can bring many benefits. But sustainable growth requires sustainable financing. Otherwise, long-time residents and local businesses will increasingly shoulder the costs while others capture much of the financial return. The discussion about housing should therefore include not only how many units we build, but also how we pay for the infrastructure that makes those homes possible. Source: City of Cambridge, Combined Sewer Overflows (CSO) Program. The City explains that approximately 55% of Cambridge remains served by combined sewers and that its Draft CSO Control Plan proposes approximately $1.3 billion in investments to eliminate CSOs in a typical 2050 year while accounting for increased precipitation associated with climate change. Learn more at: https://www.cambridgema.gov/services/combinedseweroverflows My Opinion: The Systemic Economic Downgrade of Cambridge's Mass Ave Corridor by Jeffrey Meese7/10/2026  The Bottom Line: Driven by rigid ideology rather than pragmatic economic analysis, municipal infrastructure changes along Cambridge's Massachusetts Avenue (Arlington to Central Square) are pacing toward a severe commercial and residential real estate contraction. By systematically removing parking and halving lane capacity, current policy is effectively locking out high-value consumer capital, threatening a permanent 50% retail vacancy rate. If this trajectory remains unchecked, the resulting commercial blight and concentrated institutionalized housing will cause a downgrade of adjacent residential asset values.
Key Value Drivers Under Threat
Strategic Outlook This is a case study in substandard implementation. By prioritizing ideological transit design over basic commercial logistics—like delivery zones and predictable consumer access—planners are structurally compromising the submarket. Should current trends hold, Mass Ave is on track to be systematically converted from a premier urban boulevard into a hollowed-out, institutionalized transit trough. Jeffrey Meese is an architect and realtor of residential and commercial properties.  Heat Islands Trees Map sources: City of Cambridge Key Takeaways
The City's Own Heat and Green Space Maps Tell the Story. The above two maps reflect today's Cambridge. They do not yet account for where current and ongoing redevelopment is happening and how these changes will impact our city. Cambridge is now a national leader in climate planning while simultaneously undertaking the largest expansion of multifamily housing zoning in its history. Both goals are important. The question is whether they are being planned together. The City's environmental analyses show where Cambridge is already vulnerable. Redevelopment could increase heat island intensity unless tree preservation and green infrastructure offset vegetation loss. Good planning does not require choosing between housing and climate resilience. Cities can require heat assessment and mitigation as redevelopment occurs. The question for Cambridge is not whether to build, but whether equivalent environmental safeguards are keeping pace with redevelopment. Has the City demonstrated that its housing policies and its climate resilience policies are being planned together, especially in the neighborhoods experiencing the greatest environmental stress? The next question is whether future redevelopment will reinforce or reduce those vulnerabilities. This analysis does not argue against building more housing. Rather, it asks whether Cambridge's housing policies and climate resilience goals are being planned together—and whether redevelopment is being directed toward neighborhoods already facing the greatest environmental stress. The two maps above reveal a striking pattern. Neighborhoods with the least green space generally correspond to the areas experiencing the highest summer temperatures. Eastern Cambridge—including East Cambridge, Wellington-Harrington, The Port, Cambridgeport, and Riverside—already experiences substantially greater heat stress than neighborhoods surrounding Fresh Pond and western Cambridge. Some observations stand out immediately:
Multi-Family Housing (MFH) Re-Development ImpactsCambridge's multi-family housing (MFH) ordinance policies significantly increase redevelopment opportunities throughout the city. Some of the largest changes occur in our once lower-income blue-collar neighborhoods. Many neighborhoods that historically housed larger working-class and lower-income populations already have less tree canopy, less open space, and higher summer temperatures. If redevelopment reduces remaining vegetation without meaningful mitigation, existing environmental disparities could widen. Together, these policies represent the most significant expansion of residential redevelopment opportunities in decades, allowing developments up to 5 feet from the side and rear property lines and 10 feet at the front for . Window extensions and juliet balconies can extend even further.  Where Redevelopment Meets Climate Looking at the new MFH new property development numbers neighborhood by neighborhood alongside the current city information on heat island impacts and available green spaces we can see the neighborhoods of greatest impact in terms of potential heat Island Impacts. The number of new MFH related developments (and potential new developments) in each neighborhood are listed below. These numbers are drawn from Councillor Cathie Zusy's MFH Redevelopment Tracker website : https://cambridge-redev-tracker.pages.dev/ This MFH redevelopment inventory identifies particularly high levels of redevelopment activity in Cambridgeport, North Cambridge, Neighborhood Nine and West Cambridge (the western areas of each principally), Riverside, and Mid-Cambridge. Several of these neighborhoods already are experiencing elevated heat island conditions and/or limited tree canopy. Other neighborhoods retain some environmental assets that redevelopment could gradually erode if mature vegetation and open space are not preserved: see maps above and below.  Historically, many of the neighborhoods now experiencing the greatest redevelopment pressure were also among Cambridge's more affordable communities. They often contain fewer parks, smaller residential lots, and less private green space than neighborhoods to the west. Climate resilience therefore becomes not only an environmental issue but also one of environmental equity. Upzoned Corridor HeightsOther changes are also happening outside of the MFH ordinance along our major transportation corridors, while others affect residential neighborhoods. The proposed Massachusetts Avenue and Porter Square adjacent zoning, for example, will substantially increase allowable building heights along one of Cambridge's primary commercial corridors.  Within the Porter Square Planned Unit Development (PUD) Overlay, projects may reach up to 18 stories. Much of the remainder of the corridor would permit buildings up to 12 stories. These changes dramatically increase redevelopment potential in and around Porter Square, with likely secondary effects extending into Neighborhood Nine, Baldwin, and North Cambridge. The Cambridge Street Corridor proposal will create another major redevelopment corridor across the city.  Beyond Heat: Infrastructure Under PressureHeat is only one part of the story. As redevelopment accelerates, Cambridge will also face growing demands on public infrastructure, including:
Housing production and climate adaptation are therefore closely connected. Planning for one without adequately considering the other risks increasing long-term environmental and infrastructure costs. Bringing the Whole Into ViewThe City's environmental maps identify where Cambridge is already vulnerable. The redevelopment inventory identifies where redevelopment is occurring. Recent zoning changes indicate where additional growth is most likely. The following map is a synthesis prepared by combining the City's Green Space Analysis, Urban Heat Island Assessment, the Cambridge Multi-Family Housing Redevelopment Inventory, and recent zoning changes.  Projected Environmental Stress Areas Based on Current Green Space, Urban Heat Island Conditions, Multifamily Housing Redevelopment, and Recent Zoning Changes. Viewed together these maps and datasets reveal a new geography of environmental stress. The darker orange areas represent locations where increased multifamily housing redevelopment and higher zoning intensity coincide with existing environmental vulnerability. They do not suggest that redevelopment itself is undesirable. Rather, they identify where additional investments in tree preservation, green infrastructure, stormwater management, parks, and utility upgrades may be most needed. The city's own vulnerability map reveals areas of striking concern - not only for heat island impacts but also for potential flooding.  To date the city has not been adequately testing for heat island impacts in our main residential and commercial areas.  Location of the city's 24 heat sensors across the city. 18 are run by MIT campus partners; 6 are located in other city sites. Note: none are in Alewife, North Cambridge, Mid-Cambridge or Strawberry Hill. Sources of Potential HarmHeat Island impacts can be deadly, particularly for infants, young children, seniors and other people at risk. Temperatures from one neighborhood in Cambridge to another can vary considerably. On a very hot summer afternoon, land surface temperatures can differ by 10 to 20°F between different Cambridge neighborhoods, with the hottest areas generally corresponding to neighborhoods that have the least tree canopy and the greatest concentration of pavement and buildings. Even air temperatures and perceived heat can vary noticeably over much shorter distances, particularly between shaded streets and heavily paved areas (1). Building height carries important climate implications. Research has found that taller buildings generally consume more energy per square foot than lower-rise buildings because of increased demands for elevators, water pumping, ventilation, cooling, and other mechanical systems. As the authors of one important study have concluded, "height is a significant predictor of energy use." Their study found that each additional story was associated with approximately a 2.4% increase in electricity use and a 2.9% increase in fossil fuel use, with the tallest buildings producing more than twice the greenhouse gas emissions per square foot compared with the lowest-rise buildings in the study (2). As Cambridge permits substantially taller buildings along major corridors and in current residential neighborhoods, these long-term energy and emissions implications deserve careful consideration alongside housing and climate goals. Demolitions also bring significant environmental impacts even when new buildings are built with best practices. One recent study finds that it takes 10 to 80 years for a new building to overcome even if the new one is 30 percent more efficient than an average-performing existing building due to the negative climate change impacts related to the construction process. The study calls for policy makers to acknowledge the environmental impact of sending usable buildings to landfills; strive for density without demolition; provide meaningful incentives for retention and reuse; and maintain or strengthen demolition review requirements for designated historic properties (3). Trees themselves provide multiple climate and public health benefits. They cool neighborhoods, improve air quality, reduce stormwater runoff, and absorb significant amounts of carbon dioxide. As Columbia Climate School atmospheric chemist Róisín Commane observed after her team's study of New York City's urban forest, "We already knew that street trees had this great benefit of cooling and providing shade. That they're also inhaling enormous amounts of CO₂ is an added bonus"(4). The same impact is also felt by the various trees that now dominate residential properties in Cambridge. Beyond the general environmental benefits of trees, green spaces also hold great importance. Growing evidence suggests that children raised in greener neighborhoods experience measurable developmental advantages. A Columbia University Mailman School of Public Health summary of research reports that early-life exposure to green space was associated with better visual memory in mid-childhood, adding to a broader body of evidence linking neighborhood greenery with improved cognitive development and attention in children (5). Mature trees readily reduce daytime air temperatures by 1.8–5.4°F through a combination of shade and evapotranspiration. Mature shade trees also lower the temperature of sun-exposed surfaces such as concrete, asphalt, or roofs by as much as 20–45°F - or more. As direct solar radiation is blocked by tree shade, this also reduces mean radiant (perceived) temperature by about 10–25°F, making individuals feel substantially cooler than they would feel (though measured air temperature may be higher). And this is not just about perceptions and feeling good, heat is the leading weather-related cause of death in the United States, exceeding deaths from hurricanes, floods, tornadoes in most years (6). Excessive heat especially impacts seniors, but infants and children also are impacted by related dehydration, and respiratory illness and asthma. In Cambridge, those residents living in areas of the city with higher heat island impacts, suffer these costly impacts more than other city residents. Maintaining existing mature shade trees and adding still more in our denser neighborhoods is critically important (7).  Problems with flooding: The City's own environmental analysis demonstrates that climate resilience is about more than temperature alone. Tree canopy, vegetation, and permeable surfaces simultaneously help reduce urban heat, retain stormwater, lessen localized flooding, improve air quality, and support neighborhood livability. As Cambridge accommodates additional housing, these multiple environmental services should be treated as essential infrastructure rather than incidental landscaping. The next map pair, from the City of Cambridge's Tree Canopy Assessment 2018-2024, illustrates how neighborhoods with lower heat-mitigation capacity ( which is influenced by tree canopy, vegetation, impervious surfaces, and urban density) often also have lower runoff-retention capacity, increasing flooding risks, and highlighting the interconnected role of green infrastructure in building climate resilience. Solar access is another climate consideration that deserves serious attention as building heights increase. Taller buildings can cast longer shadows on neighboring rooftops, potentially reducing the functioning of existing and future rooftop solar installations. Because Cambridge encourages renewable energy as well as building electrification, redevelopment planning should consider opportunities to preserve solar access alongside other climate resilience goals. ConclusionsCambridge has an opportunity to become a national model for integrating housing production with climate adaptation. The City's own data provide the roadmap. The challenge now is ensuring that future growth strengthens—not weakens—the environmental resilience of the neighborhoods that need it most.
Cambridge now has an opportunity to become a real national model—not simply by building more housing or by adopting ambitious climate plans, but by integrating the two. The City's own environmental data, redevelopment inventory, and zoning proposals provide the information needed to identify where additional investments in tree preservation, green infrastructure, stormwater management, and resilient infrastructure will have the greatest benefit. The challenge is ensuring that future growth strengthens—not weakens—the environmental resilience of the neighborhoods that need it most. Sources: 1. On heat island impacts in Cambridge: https://www.cambridgema.gov/-/media/files/cdd/climate/resilientcambridge/urbanheatislandtechnicalreport.pdf?utm_source=chatgpt.com 2. On building heights and energy use: Godoy-Shimizu, D., et al., "Energy Use and Height in Office Buildings," Building Research & Information (2018); quoted in Ingrid Lobet, "Getting Building Height Right for the Climate," Greentech Media, November 30, 2020. 3. On environmental costs of demolitions: https://restoreoregon.org/2021/04/12/understanding-the-carbon-cost-of-demolition/ 4. On trees and the environment: https://magazine.columbia.edu/article/incredible-environmental-benefits-nyc-trees? 5. On green spaces and childhood cognitive skills. Jiminez et al. “Early Life Exposure to Green Space Linked to Mid-Childhood Cognition” Summer 2021. Columbia University Mailman School of Public Health: https://www.publichealth.columbia.edu/research/centers/niehs-center-environmental-health-justice-northern-manhattan/news-events/newsbriefs/summer-2021/early-life-exposure-green-space-linked-mid-childhood-cognition? 6. On shade tree impacts. U.S. Environmental Protection Agency (2025). Benefits of Trees and Vegetation. https://www.epa.gov/heatislands/benefits-trees-and-vegetation; Alonzo et al.. (2025). Urban Trees and Cooling: A Review of the Recent Literature (2018–2024). U.S. Forest Service; D. H. Locke, D. H., et al. (2024). Variation in the relationship between urban tree canopy and air temperature reduction under a range of daily weather conditions. Heliyon. 7. On excess heat impacts on health: https://www.cdc.gov/heat-health/about/index.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fextreme-heat%2Fprevention%2Findex.html |