Upzoning
A change to zoning rules that allows more housing or larger buildings on a piece of land than before, for example by permitting fourplexes where only single-family houses were allowed or by raising height limits.
What Is Upzoning?
Upzoning is any change to a community’s zoning rules that increases how much housing can legally be built on a piece of land. The opposite, downzoning, reduces it. Zoning controls density through several dials, and upzoning turns one or more of them up:
- The number of homes allowed per lot or per acre
- Building height and floor area
- The building types permitted, such as duplexes, townhouses or apartments
- Related limits such as minimum lot sizes and parking requirements
How Upzoning Works
A local government usually upzones by amending its zoning map or code. The scale varies widely:
| Scale | What it looks like |
|---|---|
| Single parcel | A builder asks to rezone one site for an apartment building |
| Neighborhood or corridor | A city allows taller buildings along a transit line |
| Citywide | A city ends single-family-only zoning in residential areas |
| Statewide | A state law requires cities to allow more housing types |
Oregon’s House Bill 2001 (2019) took the statewide approach. Medium-sized cities had to allow duplexes in single-family zones by June 30, 2021. Cities in the Portland metro region and the state’s other largest cities (those with more than 25,000 people) had to allow duplexes, triplexes, fourplexes, cottage clusters and townhouses in residential areas by June 30, 2022.
Upzoning only grants permission. Whether anything gets built depends on land prices, construction costs, financing, demand and the approval process. Oregon’s land-use agency expected change to be gradual.
Why It Matters for Workforce Housing
Allowing more homes on the same land spreads the land cost across more households. That is one route to homes that teachers, nurses and other moderate-income workers can afford, often in the form of missing middle housing. Upzoning is a central goal of the YIMBY movement and a common response to a housing shortage.
Criticisms and Limitations
The evidence on affordability is mixed. A 2023 study led by Urban Institute researchers, published in the journal Urban Studies, built a dataset of land-use reforms in U.S. cities from newspaper coverage between 2000 and 2019. Reforms that loosened density limits were associated with a statistically significant 0.8% increase in housing supply within three to nine years. The gains came mostly in higher-rent units. The authors found no statistically significant evidence that lower-cost units became more available or less expensive in that period, though they could not rule out similar effects across income levels. Reforms that tightened limits were associated with higher median rents.
The same study’s review of earlier research noted that upzonings in Chicago and in Auckland, New Zealand, were followed by higher property or land prices, and that the Chicago reform did not increase supply in the period studied. For that reason, some communities pair upzoning with inclusionary zoning or density bonuses, and some residents worry that it could speed up displacement.
Sources
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