On February 10, the Cambridge, Massachusetts City Council adopted a pair of zoning reform petitions that eliminated exclusionary zoning restrictions throughout most of the municipality overnight. While major cities across the country have been adopting similar measures in recent yearsincluding Minneapolis, Austin, and SeattleCambridges reform marks an important step in tackling major affordability issues in a city long thought of as unaffordable for many, and could prove as a model for other small cities (Cambridges population is 118,000). The median sale price for a single-family house in Cambridge crested just under $2 million in 2022. Despite a brief decline since then, rental prices remain extremely high in the region, with significant increases since 2009 lows, particularly as biotechnology companies have moved into the area. The nominal 1-bedroom rental price in Cambridge currently hovers around $2,500 per month, a slight decline from 2022 highs parallel with the sales market. These trends in Cambridge are part of a larger housing affordability crisis in the Boston metro area, which has been a focal point of local politics for a number of years. Onerous zoning restrictions and the lack of a more aggressive public housing developer have stymied progress. Although Cambridge has a better track record in public housing than some municipalities, according to one of the champions of the reform, City Councillor Burhan Azeem, only 350 units were previously projected to be built in Cambridge in the next 15 years.The petitions approved last month streamline all residential neighborhoods under the same zoning code, with multifamily housing permitted in all areas except for open space. Residential construction will be allowed up to 4 stories (45 feet), or 6 stories if 20 percent of units are affordable and the lot size is at least 5,000 square feet. This will significantly shift away from the current construction market, which is dominated by single-family housing, and mark a return to a density similar to previous eras of construction, including swaths of early-20th-century housing stock whose massing and height has not been permitted in Cambridge for generations. Additional streamlining efforts within the zoning reforms will abolish step-back, Floor-Area-Ratio, and parking requirements. This will allow for more units per lot and more land to be devoted to housing, particularly as parking requirements reflect a grossly inefficient and anti-urban use of space in a city with increasingly better public transit functionality. Improvements in the petitions are significant and have the potential to radically shift not only market dynamics in housing and construction in Cambridge, but to also densify a city where parking, empty lots, and significant spans of office and research blocks limit the quality of street life. Particularly post-pandemic, parts of Cambridge, including Kendall Square, have seen large research, office, and academic projects top out. Many of the office and research clusters remain quiet day-to-day, with wind-tunnel sidewalks left empty. Zoning reform that brings more residents into the city will hopefully offset projects that directly contribute little, if anything positive, to the citys urban fabric. The other elephant in the room is the amount of land owned by universities, including apartment buildings rented on the private market to non-students.The major challenge of Cambridges growth will be affordability. While supply-side restrictions do provide leverage for landlords to continually raise rents, and an influx of construction will put pressure on that, results will still be limited without significant guarantees of low- and middle-income housing. In this area, Cambridge should learn something from New York City, where there has been backlash against affordable apartment buildings whose Area Median Income (AMI) requirements are comically high. While AMI limitations are not up to the city itself, the city will need to go out of its way to find means to support working class families and students in providing more income-restricted housing. One way to do this would be for the Cambridge Housing Authority (CHA) to take leadership as a public developer. Over 8,000 units in Cambridge are currently affordable, with only 32 percent of those under full public ownership. If the city truly wants to guarantee affordability, and recognizes the current housing shortage as a crisis, it should continue to take initiative through models of public ownership rather than waiting for the market to catch up.Chris Walton is a master of architecture candidate at Harvard GSD and a former assistant editor at AN.