Small Homes on Small Lots: How To Beat the Housing Crisis
This article was originally published, in slightly different form, on Southern Urbanism. It is shared here with permission. In-line images were provided by the writer.
An example of a small house with a detached accessory dwelling unit. (Source of original image: Sightline Institute.)
In 2019, the city of Durham, North Carolina, passed a set of reforms known as Expanding Housing Choices (or, colloquially, EHC). The reforms were created by planning staff at the directive of Durham’s City Council and were anchored by three key features:
The end of single-family zoning.
The creation of a transformative Small Lot Code.
The introduction of Reduced-Pole Flag Lots.
While relatively limited in scope, these features were almost immediately incorporated into urban development plans, creating microcommunities, more viable opportunities for citizen-built housing and, remarkably, the reconstruction of a starter-home market that had effectively collapsed.
Each of the three features outlined below contains elements that other cities should emulate:
1. The End of Single-Family Zoning
Single-family zoning has an ugly history in the United States, one clearly rooted in racial motivation. The first such code started in Berkeley, California, in 1916 as a means of limiting access for the less wealthy who, at an acute moment of racial strife, happened to be Black. After the passage of the Fair Housing Act in 1968, politics drove planners to radically expand single-family zoning, with many cities implementing it for the first time. It is no coincidence that Durham’s first instance of a single-family zoning code was passed in 1969.
When discrimination based on race became illegal, exclusion became a game of Whac-A-Mole through increasingly technocratic proxies, none more effective than single-family zoning. There were others, too, all related to single-family considerations, such as mandating large lots with large setbacks, large parking requirements and large lot widths.
All of these rules added costs to housing, intentionally discouraging those with less wealth.
Durham’s code even created a racial distinction between the most dominant urban zoning districts, RU-5 and RU-5(2), by permitting duplexes in black neighborhoods while disallowing them in white ones. All of that came to an end with the passage of EHC, when Durham’s City Council repealed single-family zoning exactly 50 years after it was enacted.
Practically, what does getting rid of single-family zoning mean?
In Durham, a few things changed:
Builders and homeowners could now build duplexes, by right, and “attached homes” (which are effectively just duplexes with fee-simple lot lines).
Accessory dwelling units (also called backyard cottages or ADUs) became allowed on duplexes as well, potentially yielding a total of three homes on most lots.
Duplexes could be detached, triggering a wave of opportunities for what incremental developer R. John Anderson calls “stealth pocket neighborhoods,” a housing type that does not depend on being specifically allowed by the code. In Durham, urban designers can use the existing code that allows three homes on a lot and arrange those homes in a way that enhances community space to the benefit of all.
New construction rental projects that were not financially viable before suddenly became so by spreading expensive land costs across multiple houses. This helped restart a mostly dormant neighborhood-scale rental housing market. This market includes homeowners who, when building their own house, can now build two additional homes, which can pay for some (and sometimes all) of their mortgage. A select few homeowners have acknowledged the truth of this seemingly unbelievable math: The best way to create affordable housing for yourself is to simultaneously provide some for others. And just like that, citizens are getting back into the game of homebuilding.
2. The Small Lot Code
The most unprecedented and transformative reform in EHC is the introduction of the Small Lot Code. This allows for new homes to be built on lots up to 2,000 square feet, contingent on the home having a maximum of 1,200 square feet of livable space and an 800-square-foot footprint, as well as being a maximum of 25 feet tall (measured to the midpoint of the roof in 2019, but reformed to allow for a 32-foot ridge in 2023). It also allows for smaller corner setbacks, which are necessary in a city with largely anti-urban front yards.
The Small Lot homes may also be duplexes (dividing the 1,200 square feet between the units) and have detached ADUs that allow for an additional 1,200 square feet.
The Small Lot provisions have been adopted faster than expected, with more than 50 units already built and more than 100 in the pipeline (2022 data). Astonishingly, it appears that the majority of new detached homes being built in the urban tier of Durham are ones with Small Lot permits.
The effects of this code can be seen in the area’s average home prices. Durham has generally been the tightest, most sought-after market within the Triangle region. However, the provisions of the Small Lot Code appear to have already “bent the price curve,” reintroducing starter homes into a city that has a population of over 250,000 — and which recently announced major Google and Apple campuses and has had speculators rushing into town to buy homes sight unseen. Since 2020, Durham has had 50 new detached homes sell for less than $500,000, while Chapel Hill and Raleigh have had zero. That’s the Small Lot Code at work.
Another consequence has been the cottage industry of designers that quickly formed to service this market. For example, Bill Allison is a veteran architect with Allison Ramsey Architects and is armed with a catalog of 3,500 stock plans — all Southern traditional. He created a set of plans that conformed specifically to Durham’s code.
In addition to the dozens of plans done pro bono for affordable housing in Durham, he’s had multiple local builders purchase Small Lot plans, too. As Allison put it, offerings like his make it easier for people to go down this path: “Small homes are great, but they require a lot of design nuance. Once you understand the constraints, you can create efficient spaces, and you can arrange multiple small homes to create a uniquely Southern urban experience. Tall windows, deep porches, eave details, and so on.”
3. Reduced-Pole Flag Lots
Durham also implemented a unique Reduced-Pole Flag Lot (RPFL) option based on community feedback that the previously required pole width of 20 feet was effectively unusable. Reducing the required pole width to 12 feet while restricting homes on these lots to the same dimensional standards as above created a wealth of opportunities for small, rear-located housing that could never have been built before. The RPFL option has become a critical tool for exploring the potential of microcommunity developments. Such possibilities now seem endless, and entrepreneurs are drawing up new business plans that provide more housing — and better housing — in community-enhancing formats than have ever been seen in Durham before.
National Implications
To all but the most ardent NIMBY voices, EHC has been a success. President Biden even borrowed the program’s language for his Housing Supply Action Plan (Fannie Mae did similarly, as did San Francisco).
It’s been strange to see Durham not get more press for the reforms. Perhaps this is a function of the city's lack of self-promotion or its relatively small size. However, the EHC provisions are clearly valuable, and cities across the nation should examine them and their results.
If we are to keep cities and towns accessible and affordable while also urbanizing them and making them walkable and beautiful, there are no pain-free approaches. Such work is overwhelmingly incremental and requires densifications at the margins. The West Coast shows the clear costs of only permitting homes for the rich. Over time, it’s disastrous for everybody. Small, incremental homes on small lots — that’s the way forward.
Durham has taken that step better than anyone. Now, others should follow.
Learn more about encouraging incremental housing in your place with the Local-Motive session on September 26: “Investing in Housing Development that Strengthens Neighborhoods Without Pushing People Out.”
Aaron Lubeck is a award-winning restoration contractor specializing in historic restorations, as well as a faculty member with the Incremental Development Alliance, where he specializes in zoning reforms. He is the author of a children’s book on accessory dwellings entitled “Heather Has Two Dwellings,” as well as “Green Restorations: Sustainable Building and Historic Homes.”
Most recently, Aaron is the founder and development director for Southern Urbanism, a Durham-based nonprofit committed to building better cities in the South. He writes at Southern Urbanism Quarterly and on his personal blog, “onHousing.” He tweets at @aaron_lubeck.
