Sprawl zoning is unsustainable

  • The way much of Cambridge is built is good for the environment. The way Cambridge is zoned is not.

  • We need better zoning to protect and grow our walkable, eco-friendly neighborhoods and make them available for all.

Sprawl Zoning Hurts the Environment

We are proud of our city’s commitment to sustainability. Cambridge’s density, as well as its small businesses, community resources, institutions, and parks, and public spaces make it an easy place to live car-free. Cambridge is also expanding our commitment to resilient development and climate justice; we’ve laid out ambitious goals to reduce our carbon footprint and make a positive environmental impact on our city, region, and planet.

Unfortunately, our current “sprawl zoning” is in conflict with this commitment. This approach to zoning does not reflect the inherent sustainability of our historically dense neighborhoods. Furthermore, it is standing in the way of our climate goals by limiting new “missing middle” housing, such as duplexes, triple-deckers, and other slightly denser building types, that better reflect our environmental values.

Our Current Zoning Forces Bad Environmental Choices

Cities create less greenhouse gases per capita than suburbs. While Cambridge’s existing dense neighborhoods are some of the greenest in the state - at least 65% of Cambridge existing neighborhoods could not be built under today’s zoning. Despite incorporating high standards for energy efficient and resilient buildings in large projects, Cambridge’s current zoning code facilitates unsustainable land use patterns in our neighborhoods.

Parking Minimums

Current residential zoning requires off-street parking for each new unit built. Forced car storage:

  • Incentivizes car ownership and driving, increasing our carbon emissions and air pollution,

  • Requires more impermeable surface,

  • Leaves less space for trees, gardens, and homes,

  • Limits space for street trees by requiring curb cuts for driveways.

Strict Dimensional Maximums

  • Current floor-area-ratio (FAR) and height maximums limit both the building footprint and height.

  • When homes can’t grow up or out, they shrink and house fewer people.

  • This means fewer people are able to live in neighborhoods that support a low-carbon lifestyle.

  • Single-family homes require more energy to heat than multi-family homes, like townhouses and fourplexes.

Car storage - including access paths - takes up significant space

Dwelling Unit Caps

  • Current limits on the number of units allowed on a lot exclude residents, who cannot afford high market rents or purchase prices.

  • As housing costs rise and displacement of low- and middle-income residents continues, people working in Cambridge are pushed into cars and commutes in from suburbs and exurbs.

  • If people who work here can’t afford to live here, we are creating more traffic, more emissions, and air pollution from long commutes, and weakening our community.

Setback Requirements

  • Excessive setback requirements force buildings further apart, which makes creating walkable neighborhoods more difficult.

  • Buildings that are spread further apart also make serving areas via public transit more difficult, forcing longer routes and more stops.

Zoning for Sustainable Neighborhoods for All

In sharp contrast with the limits of low-density residential zones, the Missing Middle Housing Zoning Amendment's proposed “Res N” zoning would:

  • Legalize car-free housing development, allowing units to be developed instead of parking spaces as-of-right,

  • Preserve a high open space percentage citywide - allowing three-story housing on up to 40% of the lot,

  • Create flexible dimensional standards and increase dwelling unit caps. With slightly more units per lot, more Cambridge residents will:

        • Have access to more private open space

        • Share our walkable communities

        • Reduce their carbon footprint.

Our proposed setbacks and open space minimums will create livable homes, preserving residential comfort and privacy while incentivizing green, permeable spaces on private property. Owners will have the flexibility to create shade trees, native plantings, and setbacks that are consistent with surrounding homes - Res N will help owners reduce their building’s carbon footprint.

This zoning reform reflects key climate goals from Envision Cambridge, including:

  • Ecological Protection, reducing pollution and enhancing Cambridge’s biodiversity, open spaces, and habitats; and

  • Environmental Justice, ensuring that Cambridge residents are protected from environmental impacts and benefit equally from environmental resources and health.

Permeability and Private Open Space

The proposed neighborhood zoning (“Res N”) preserves open space requirements and will support high percentages of permeable and native landscaping that doesn’t require irrigation. Residential zones that currently cite low FAR maximums (e.g. Res A) also have the highest percentage of impervious land per unit (see Figure 1); linking denser development with both open space and no parking requirements will support the inclusion for permeable space citywide.

The Missing Middle Zoning reform will help match Cambridge's zoning to both our built environment and our values of environmental justice, access to affordable housing, and neighborhoods for all.

Neighborhoods with exclusionary zoning have more impervious surface per dwelling unit than other residential neighborhoods.