State Housing Supply
Legislative Tracker
Legislative Tracker
280,000*
potential new homes per year
“Small Lots, Small Lots, Small Lots”
Summary of introduced bills from 14 states having total or partial alignment with AEI Housing Center Playbook Options 1-3. Total projected extra homes per year: 280,000 (assuming KISS followed and no poison pills).
Right most column shows the bill’s percentage Playbook alignment with one or more options: Complete: ≥100%, Substantial: 51%-99%, Moderate: 15-50%, and Weak: <15%. ✓ = bill passed.
Ranked by annual supply increase. Click a state for details.
Data is limited to cities with a population of at least 50,000. City population totals use the higher of the 2023 ACS 1-Year or 5-Year survey population estimates. Under a minimum density of 6 units per acre, we assume lot sizes must be at least 7,260 sq.ft. (43,560 / 6) in order to be eligible for a lot split.
Assumes ADUs are built on land up to a 100% land share.
Only applies to new residential subdivisions that are 4 acres or larger in size. To determine subdivision sizes, we define a contiguous subdivision as a cluster of 10 to 5,000 new single-family homes built in subdivisions that share the same subdivision name within the same city. Homes in contiguous subdivisions with missing subdivision names are omitted. 99.7% of homes built in subdivisions since 2000 in Idaho had subdivision names. In calculating and applying contiguous subdivision sizes, a 30% allotment is included to account for streets. 76% of new subdivisions built since 2000 in Idaho are at least 4 acres in size. At a minimum lot size of 1,500 sq.ft., we assume a distribution of lot sizes that yields approximately 13 homes per acre on average. Data is limited to cities with a population of at least 10,000. City population totals use the higher of the 2023 ACS 1-Year or 5-Year survey population estimates.
Data is limited to cities with a population of at least 5,000. City population totals use the higher of the 2023 ACS 1-Year or 5-Year survey population estimates. Assumes ADUs are built on land up to a 100% land share.
At a minimum lot size of 2,500 sq.ft., approximately 11.5 homes per acre on average are assumed. Lots eligible for conversion must be between 2,501 and 5,000 sq.ft. to be split into four lots, 5,001 and 7,500 sq.ft. to be split into six lots, and > 7,500 sq.ft. to be split into 8 lots.
Assumes ADUs are built on land up to a 100% land share.
For Option #1, data excludes homes with living area >= 3,000 sq.ft. and lot sizes > the 90th percentile (~15,700 sq.ft.). For Option #2, data excludes homes with living area >= 3,000 sq.ft. At a minimum lot size of 3,000 sq.ft., approximately 11 homes per acre on average are assumed.
Growth area designations are made at the municipal level through each town's comprehensive plan; as a proxy for growth areas, Census urban land designations are used. As a proxy for public water and sewer access, tract size and density are used. Tracts with 95%+ of all homes on a half-acre or greater and average density <= 1.5 homes/acre are excluded. At minimum lot sizes of 5,000 sq.ft. and 1,250 sq.ft., approximately 10 and 13.5 homes per acre on average are assumed.
Limits to counties with a population of 150,000 or greater. County population totals use the higher of the 2023 ACS 1-Year or 5-Year survey population estimates.
Limits to counties with a population of 150,000 or greater. County population totals use the higher of the 2023 ACS 1-Year or 5-Year survey population estimates.
For this analysis, the 10,000 sq.ft. cap applies only to new residential subdivisions, corresponding to Option #1 of the Playbook. For lot splits, up to 5 are allowed on land with public water and sewer access, and up to 3 are allowed on land without water and sewer access. ADUs are assumed to a by-right use on all land regardless of water/sewer access. The Massachusetts Department of Environmental Protection publishes water and sewer utility service boundaries. We mapped homes in our property-level data to these boundaries for the Option #2 analysis.
For this analysis, the 10,000 sq.ft. cap applies only to new residential subdivisions, corresponding to Option #1 of the Playbook. For lot splits, up to 5 are allowed on land with public water and sewer access, and up to 3 are allowed on land without water and sewer access. ADUs are assumed to a by-right use on all land regardless of water/sewer access. The Massachusetts Department of Environmental Protection publishes water and sewer utility service boundaries. We mapped homes in our property-level data to these boundaries for the Option #2 analysis.
For Option #1, data is limited to properties with public water and sewer access. Michigan does not publish data on public water and sewer access; thus, as a proxy for public water and sewer access, we use tract size and density. Tracts with 95% or more of all homes are on a half-acre or greater and an average density of less than or equal to 1.5 homes per acre are excluded from all calculations. At a minimum lot size of 1,500 sq.ft., we assume a distribution of lot sizes that yields 13 homes per acre on average.
For Option #1, data is limited to properties with public water and sewer access. Michigan does not publish data on public water and sewer access; thus, as a proxy for public water and sewer access, we use tract size and density. Tracts with 95% or more of all homes are on a half-acre or greater and an average density of less than or equal to 1.5 homes per acre are excluded from all calculations. At a minimum lot size of 1,500 sq.ft., we assume a distribution of lot sizes that yields 13 homes per acre on average.
Assumes ADUs are built on land up to a 100% land share.
County population totals use the higher of the 2023 ACS 1-Year or 5-Year survey population estimates. Data is limited to counties with a population greater than 700,000.
Assumes ADUs are built on land up to a 100% land share.
See Option #3 total for North Carolina state Playbook here: https://heat.aeihousingcenter.org/toolkit/housing_playbook.
All estimates are limited to municipalities with a population above 50,000 in counties with a population above 275,000. As a proxy for public water and sewer, tract size and density are used. At a minimum lot size of 1,200 sq.ft., approximately 13.5 homes per acre on average are assumed. For Option #2, lot splits of up to 10 are permitted if each lot meets the 1,200 sq.ft. minimum.
Assumes ADUs are built on land up to a 100% land share.
Assumes ADUs are built on land up to a 100% land share.
Data on public water and sewer access are obtained from the Rhode Island Geographic Information System Water Supply Districts and Sewered Areas. For minimum lot sizes of 2,500 and 5,000 sq.ft., approximately 11.5 and 8 homes per acre on average are assumed. For Option #3, data is limited to municipalities with a population greater than 40,000. The 30% commercial residential overlay mandate is applied as a 30% multiplier to each eligible municipality's Option #3 total.
Assumes ADUs are built on land up to a 100% land share.
Data is limited to counties that are required to fully plan under Washington's Growth Management Act with a population of 30,000 or greater. County population totals use the higher of the 2023 ACS 1-Year or 5-Year survey population estimates.
Data is limited to counties that are required to fully plan under Washington's Growth Management Act with a population of 30,000 or greater. County population totals use the higher of the 2023 ACS 1-Year or 5-Year survey population estimates.
Data is limited to areas outside of urban growth areas, as defined by Washington state. Urban growth area boundaries are obtained from the Washington State Geospatial Portal. This bill is entirely opt-in; the actual impact may be less than estimated. Assumes ADUs are built on land up to a 100% land share.
This tracker monitors state-level legislation that could increase housing supply by reforming local zoning regulations. The bills tracked here align with the AEI Housing Center’s State Playbook, a comprehensive guide for state legislators to unlock housing production through targeted reforms.
The annual supply increase percentage compares projected new homes from proposed legislation to the average number of homes built per year in each state from 2010-2023 (according to American Community Survey data). For example, +107% means the legislation could more than double the state’s typical annual housing production.
The AEI Housing Center Playbook identifies three state-level options to unlock new housing supply using small lots:
KISS (Keep It Short and Simple) reforms eliminate unnecessary complexity in the homebuilding process. These include:
Each bill is rated on how closely it aligns with the Playbook’s recommended provisions, measured as a percentage of the Playbook option’s projected homes:
* Housing supply projections depend on KISS implementation. “Poison pills” such as rent control, income requirements, and/or municipal discretion can reduce or eliminate benefits. Projections assume that bills with similar reforms are independent from one another. See the playbook for more detail.