- US cities are turning to infill housing solutions by relaxing zoning restrictions to unlock development on “hidden plots”—odd-shaped or leftover urban parcels.
- More than 250 zoning rule changes and nearly 180 state-level housing laws have been passed in the last two years to support denser, more flexible housing development.
- These changes aim to tackle the “missing middle” housing gap and reduce costs by allowing multi-unit construction on land previously deemed unbuildable.
Rethinking The Urban Footprint
As urban housing shortages escalate, cities are embracing a creative fix: building on land that was once considered unusable, reports GlobeSt. Known as “hidden plots,” these include narrow strips, odd corners, and leftover shapes between existing structures. While traditionally ignored by developers, new zoning laws are opening the door for them to become viable housing sites.
A Wave Of Policy Reform
According to The New York Times, city governments and state legislatures are aggressively changing zoning laws to encourage density. ReZone AI found that the 250 largest US metro areas passed 257 zoning updates in the past year alone. Pew reported 96 state laws supporting housing development between 2023 and 2024, with 80 more already enacted in 2025.
Reforms include reducing or eliminating minimum lot sizes and parking requirements—key obstacles to using irregular parcels. Additionally, some building codes have been updated to allow for single stairwell designs in multifamily buildings, making construction on tight lots more feasible.
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Addressing The “Missing Middle”
These efforts directly target the “missing middle”—the lack of duplexes, triplexes, and townhouses between single-family homes and large apartment complexes. Experts say this type of housing is key to both affordability and urban revitalization. Odd-shaped lots often sell at lower prices, making them more appealing to developers. As a result, building multi-unit homes on these parcels helps spread construction costs and reduce prices for buyers.
“If you put a triplex on that land, you bring down the cost enough where you can find buyers,” said Arica Young of the Lincoln Institute of Land Policy.
Early Movers
Cities like Seattle, San Francisco, New York, and Minneapolis are already adopting these reforms, proving that even the most awkward spaces can become new homes. As land prices remain high and urban space scarce, expect more municipalities to follow suit.
Why It Matters
Relaxed zoning is rapidly reshaping what’s buildable in US cities. For developers, hidden plots now represent low-cost entry points into tight housing markets. For cities, the reforms offer a scalable way to expand housing supply—without sprawl.
What’s Next
With hundreds of new laws already on the books and more cities eyeing reform, infill development could become a defining trend in urban housing. As creative design meets relaxed regulation, the overlooked corners of America’s cities may soon be filled with new homes—and new possibilities.
