Passing ambitious legislation matters for obvious reasons, but so too does the rule-making process that follows a law’s passage. Final language often leaves state agencies with tremendous leeway, and real-world impact can vary widely based on administrative decisions that often get far less public scrutiny. Political scientist Leah Stokes calls this the “fog of enactment,” which opens the door for better-resourced interest groups and engaged insiders to water down the impact of landmark legislation.

Responding to years of advocacy for zoning reform, the Legislature recently passed a new Transit Oriented Development (TOD) law requiring cities and towns in the MBTA service area to create at least one zoning district that legalizes modest multi-family housing construction of at least 15 units per acre. The new law is a great opportunity to address our region’s housing crisis, but critical details remain to be worked out through a complex rule-making process involving the Department of Housing and Community Development (DHCD), Department of Transportation (DOT), and the MBTA - which could last for much of the coming year. Depending on where this process lands, this promising new law could in practice net thousands of new homes – or almost none.

This law has promise because far too many cities and towns in our region have adopted single-family-exclusive zoning districts, making it illegal to build modest, affordable types of homes like small apartments, townhomes, and even the classic Boston triple decker. As a result, we don’t build enough homes for everyone who’d like to live in our region, and what we do build is skewed towards expensive single-family homes since in many places they are the only things you can legally build. The pandemic has heightened this problem, as demand for living outside the urban core accelerated. Increased demand for homes in the region’s suburbs presents an opportunity to build a more equitable region and revitalize some struggling regional downtowns, but if we maintain bans on multifamily housing construction this increased demand will only lead to ever-higher housing costs.

Greater Boston’s tony suburbs are the most aggressive in maintaining single-family-exclusive zoning, serving to exclude families with lower incomes, who are disproportionately Black and Latino. Present day single-family-exclusive zoning districts closely mirror historic redlining maps, which excluded Black families in particular from receiving federally-backed home loans. Anything we do to change these rules is therefore one of the most powerful local steps we can take to advance racial justice and reduce income inequality here in Greater Boston.

With this context hopefully motivating us to maximize the new TOD zoning law’s potential, following are three principles that we think should guide DHCD in writing the final rules:

• Maximize the definition of “reasonable size.” The law states that every MBTA community needs to legalize multifamily housing in a district of “reasonable size” somewhere within a half-mile radius around a transit stop. Much hinges on how “reasonable size” is determined. We encourage the rule-makers to define it as large as possible because the ultimate point of this law is to generate actual new multifamily homes in transit-rich areas. We’d go so far as to say these zones should take up all residential and mixed-use land within the full ½ mile radius around a transit stop—there’s really no reason to require property owners to build only single-family homes within walking distance of transit stops.
• Discourage locating new multifamily districts in places where multifamily housing already exists. Equally important is ensuring that new zoning districts consider the housing stock already in the district and prohibit towns from creating a “new” multifamily district by drawing a circle around existing apartment buildings that are currently at or near the 15 units per acre density threshold. If this were to happen, we might on paper add a bunch of new multifamily districts while not actually yielding any significant new housing construction. This new law needs to increase actual zoned capacity enough so that local home builders will actually use it. To the extent that the law’s language as adopted makes this difficult to fend off through rule-making, the legislature should consider follow-on legislation that better defends against this practice.
• Minimize the use of procedural barriers. Finally, we need to do everything we can to ensure that implementation protects against all the varied procedural tools municipalities have to drag their feet in authorizing new housing. While it’s important that the law requires the zoning to be as-of-right, the rulemaking should not allow municipalities the wiggle room to use things like parking/dimensional requirements, discretionary design reviews, excessive environmental impact, or historic preservation, to effectively limit the impact of this law. While some local review does make sense, the guiding principle should be allowing for the construction of reasonable multifamily housing as-of-right. These local barriers can be hard to pre-emptively cut off through rule-making, but it’s important for the rule makers to consider how municipalities have historically used procedural barriers to stop new housing.

Ultimately, our state’s efforts to increase the availability of diverse housing options is a work-in-progress. The new TOD law was passed through an omnibus economic development bill, and so did not go through a full vetting process. Maximizing the potential of the current TOD rule-making process will help tremendously, and we should be prepared to keep working through future legislation as well. Our ability to shape an inclusive, thriving region depends on it.