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

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.
FULL STORY: This “Multigenerational Roommate House” Shows How To Heal the Housing Market

What ‘The Brutalist’ Teaches Us About Modern Cities
How architecture and urban landscapes reflect the trauma and dysfunction of the post-war experience.

‘Complete Streets’ Webpage Deleted in Federal Purge
Basic resources and information on building bike lanes and sidewalks, formerly housed on the government’s Complete Streets website, are now gone.

Downtown Los Angeles on the Rise: A Promising 2025
Fueled by new developments, cultural investments, and a growing dining scene, downtown Los Angeles is poised for significant growth in 2025, despite challenges from recent wildfires and economic uncertainties.

San Francisco Slow Streets Bucks Citywide Trend, Reducing Injuries by 61 Percent
Low-cost interventions aimed at slowing traffic are making a major impact on road safety.

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?

Report: Transportation Equity Requires More Than Electrification
Lower-income households often lack the resources to buy electric cars, signaling a need for a more holistic approach to improving mobility and lowering transportation costs.
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Economic & Planning Systems, Inc.
UCLA Lewis Center for Regional Policy Studies
Mpact (formerly Rail~Volution)
Chaddick Institute at DePaul University
City of Piedmont, CA
Great Falls Development Authority, Inc.
HUDs Office of Policy Development and Research