How Single-Family Conversions Benefit Both Homeowners and Cities

Converting single-family homes to triplexes can ease the housing crisis and offer affordable, flexible options for more households. Why is it largely illegal?

1 minute read

March 4, 2025, 10:00 AM PST

By Diana Ionescu @aworkoffiction


Two pastel green/blue front doors on duplex with decorative wreaths.

Jason / Adobe Stock

A “Multigenerational Roommate House” outside of Dallas offers a model for affordable multifamily housing — if only it’s made legal in more places.

The home’s owner, Monte Anderson, “applied some savvy interpretation of local zoning rules to transform it into a legal, owner-occupied, multiunit home for five single adults ranging in age from almost twenty to over 70.” The units have separate entrances, bathrooms, and kitchenettes (full kitchens would trigger a zoning violation).

This style of housing is illegal under most U.S. zoning codes, explains Lauren Ronnander in an article for Strong Towns. But advocates for reform argue that allowing single-family conversions to duplexes or triplexes “can give residents the flexibility to live where they want at a price they can afford.”

According to Ronnander, allowing duplex conversions can also raise property values and, in turn, local tax revenue, benefiting cities. “In cities that make this type of housing legal by right, thousands of stagnant properties can be improved, raising property values, increasing tax revenue and revitalizing aging neighborhoods.” Legalizing single-family conversions can create more housing choices while avoiding the opposition and infrastructure costs that come with larger multifamily projects.

Monday, March 3, 2025 in Strong Towns

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