Connecticut Zoning Atlas
The Connecticut Zoning Atlas is a first-in-the-nation interactive map showing how an entire state zones for housing. It has now become part of the National Zoning Atlas. Click on the Atlas below to explore. To make corrections, updates, and questions, please contact us.
For a summary of key findings, click here.
What Kind of Housing is Allowed in Each Town?
According to the Atlas, single-family housing is allowed as of right on 90.6% of the land in Connecticut. We have also mapped every district that permits two, three, and four+ family housing. The numbers are 27.6% for two-family, 2.5% for three-family, and 2.2% for four+ family.
Single-family housing is allowed as of right in 99.6% of the land shown as Primarily Residential Zoning, and 70.2% of land zoned as PRZ only allows single-family housing as of right, and no other kind of housing as of right.
Nine towns allow only single-family housing, and no other kind of housing.
Where are Accessory Apartments Allowed?
According to the Atlas, as of 2022, accessory apartments are allowed in nearly every town in the state: 94% of towns allow accessory apartments in some form or fashion. 89.9% of land allowing residences of any type also allows accessory apartments, and 49.7% of such land allows accessory apartments “as-of-right” (meaning, without costly public hearings or onerous application requirements). 94 towns (56% of all towns) allow accessory apartments as-of-right in at least one zoning district, and 81 (49%) allow such units as-of-right in a majority of zoned land.
That said, stringent and inconsistent rules make it difficult for people to build accessory apartments, or even to know how they must build this type of unit. As a result of HB 6107, accessory apartments are now allowed as-of-right on all single-family lots (unless a town opts out). Our map tracks pre-2022 regulations and will be updated in January 2023.
What is Allowed Around Train Stations?
Transit stations (train and CTfastrak stations) are where we should be creating walkable, mixed-use transit-oriented communities. Unfortunately, most towns have large-lot single-family zoning and ban or prohibit multi-family housing around transit stations. Click on the “Rail, CTfastrak, and Ferries” box in the Zoning Atlas to see a half-mile radius around each station. Explore whether your town adequately permits the kind of housing that would open housing opportunities to more families. And join us in advocating for better zoning in these areas.
Do Towns Allow Walkable, Mixed-Use Neighborhoods?
Some towns already allow neighborhoods with 2-or-more family homes around shops and restaurants, though few allow such housing as of right. As with transit areas, walkable, mixed-use neighborhoods provide an important opportunity for equitable growth. Join us in advocating for zoning that enables walkable communities.
Where can I find more information about the research itself?
For a summary of key findings, click here. For a methodology plus how-to guide to create an atlas in your jurisdiction, click here. Additional research grounded in the Atlas will be published in the months and years ahead.
What Does the Zoning Atlas Mean?
People around the state have used the Zoning Atlas to see how their town fares. Its implications for advocacy and policy have been covered by the New York Times, Courant, the CT Mirror opinion, CT Mirror reporting, WNPR, and the New London Day, among other places, and its reference in the PBSNewsHour segment is featured below.
PROJECT TEAM
Director: Sara C. Bronin
Geospatial Lead: Ilya Ilyankou of the Connecticut Data Collaborative
Geospatial Map Coordination: Cary Chadwick
2020-2021 Zoning Code Analysis: David Block, Giacomo Cabrera, Sarah Cherfan, Constance Chien, Emma Cotnoir, Josephine Cureton, Taylor Dallin, Sophia De Oliveira, Giuliana Duron, Maxine Faisant, Kevin Fitzgerald, Christopher Gelino, Kathleen Gibbons, Erin Hill, Emily Karr, Jared Klukas, Andrea Lee, Sunnie Liu, Lucia O’Sullivan, Natalia Perez, Emily Tian, Isaiah Wright
2020 Geospatial Map Collection Assistance: David Dickson, Mark Hoover, Quinn Molloy, Emily Wilson
Special Thanks: The Community Foundation of Eastern Connecticut for generous grant funding and the municipal planners of 63 towns, who confirmed data accuracy