
Part 2 in a series discusses how making it easier to build more, smaller houses would bring down home prices and help bring back the starter home. Read Part 1: “How re-legalizing starter homes cuts new house prices.”
Legalizing “missing middle housing” allows homebuilders to “make it up on volume”: sell a higher volume of units, each at a lower price, by lowering the cost of inputs per unit. Those lower costs come from both dividing land and materials between multiple units, and building smaller units that use fewer materials.
Much has been written about how Houston reduced minimum lot sizes, spurring a wave of moderately-priced townhouses. Yet Houston’s famously unusual land use regulation may make comparisons difficult. Instead, let’s look at three growing (but conventionally zoned) cities that have changed their zoning codes recently to allow smaller houses, and seen homebuilders respond with hundreds of new, lower-priced homes.
Petite prices in Portland
In 2021, Portland passed a controversial zoning reform called the Residential Infill Program, or RIP; in 2022, it followed with “RIP2,” which ended its 1950s minimum lot size rules. This allowed homebuilders to profitably build smaller houses on smaller lots that sell for less money, and builders enthusiastically responded by building “starter homes” in both size and price.
Builder magazine profiled homebuilder Eric Thompson, who pivoted his business from Oregon HomeWorks, which sold million-dollar teardown mansions, to Snug Homes, which sells cottages and townhouses at half the price. Despite cutting prices in half, Thompson “is seeing the same profit margins as before but on more revenue, resulting in a healthier bottom line.”
A recent city report reviewing RIP’s effects included this pair of graphs, showing new house prices and sizes in established residential neighborhoods in Portland in 2024. Detached houses on conventional lots (which would have been legal before RIP) are shown on the left, and denser “middle housing” (which was legalized by RIP) on the right.
Two graphs from a recent City of Portland report, showing the prices and sizes of recently built new houses. Image used with permission.
With houses, more money buys more house; after all, “price per square foot” is a common unit price for homebuyers. Yet even for conventionally sized houses, the demand is greatest for smaller and cheaper houses; note that the house dots on the left graph cluster around 1700 square feet and $600,000. Yet it’s difficult to sell a new house on a conventional Portland lot for less than $500,000.
What’s surprising is the graph on the right, which shows that the zoning change resulted in many new, smaller units that actually sell for less: “In 2023-24, the average sales price of a new market-rate middle housing unit was about $250,000 to $300,000 less than that of a new market-rate single detached house, mostly due to size difference.” New houses on unconventional lots almost all sold for less than $500,000, the citywide median house price.
As homebuyer Josie Cantu enthused to NBC News, “these kinds of buildings being put in place opens up so much opportunity for people like myself.” Many of the new houses (the light blue dots) are even priced low enough to qualify for pre-existing affordable homeownership programs, greatly expanding those programs’ reach and making homeownership even more attainable for moderate-income and middle-income Portland residents.
Another finding of the city’s report is that there has not been a significant increase in residential demolitions. The pace of demolitions has remained roughly steady, but the city now sees twice as many units built per demolition.
Durham bent the curve
Similar new zoning rules enacted in 2019 also re-legalized the starter home market in Durham, North Carolina. Local homebuilder Aaron Lubeck writes in Southern Urbanism that “the most unprecedented and transformative reform in EHC is the introduction of the Small Lot Code,” which allowed existing city lots to be subdivided for small houses on small lots, and effectively allowed new houses on what were unused back yards and front yards.
The Small Lot Code was quickly embraced by builders; by 2022, small lots accounted for the majority of new-construction houses sold in central Durham. It’s no surprise that they’re popular: some new small-lot houses sell for less than $300,000, compared to the city median of over $400,000. Lubeck points out that the explosion of new small houses caused new-home sales prices citywide to plateau in 2022, even as prices in neighboring Raleigh and Chapel Hill (and nationally) continued to climb.
Denser, smaller new houses are less expensive than larger new houses near Drew Street in Durham. Screenshot of real estate listings from Redfin.com.
Recent sales near the corner of Hanover and Drew streets, one mile from the center of Durham, illustrate how small lots have transformed the city’s new housing market and created more housing choices. These sales include:
- a new, large detached house for $915,000;
- a new, mid-sized four-bedroom house for $515,000;
- a new small, two-bedroom house for $345,000; and
- an older house for $362,000.
The $345,000 two-bedroom house – effectively an accessory dwelling unit sold separately – is comparable in price to the nearby $362,000 house from the 1950s, but with the advantages of new construction (better efficiency, more usable interiors, newer systems). That price was possible because they split the large lot with the larger, $515,000 houses in front. Together, the $515,000 and $345,000 houses add up to $860,000 of house on one lot – about as much as the $915,000 new house on a full-sized lot a block away, but divided such that two families can combine their purchasing power to buy that one city lot.
Twins win in Raleigh
The new duplex units on the left sold for much less than the new detached house on the right. Image by the author.
Durham’s success later inspired the city council down the road in Raleigh toward two broad zoning text changes in 2021 and 2022 that have been among the most productive “missing middle housing” reforms in America, with nearly 4,000 formerly impossible units permitted to date.
One of the most notable early changes was allowing duplexes on every residential lot, a change urged by city councilor Jonathan Melton: “If someone can build a mansion next to my house and I have no say…because that’s their property and that’s allowed by right, why do I have to weigh in if someone can build a duplex or a quad or some townhomes? What message are we sending about the types of people that live in big, single-family, expensive homes, and the types of neighbors we welcome into multifamily living?”
The results were very quickly seen in neighborhoods which were already seeing teardowns and mansionization. Because duplexes can be built and permitted almost exactly like detached houses, some teardowns that had already happened went back and reapplied for permits as duplexes instead.
Denser, smaller new houses are less expensive than larger new houses on Sheffield Road in Raleigh. Screenshot of real estate listings from Redfin.com.
On Sheffield Road in east Raleigh, a few blocks from where I went to high school, two neighboring new houses sold in 2024. On one side, a new four-bedroom detached house sold for $865,000; next door, a four-bedroom duplex unit sold for $660,000 – over $200,000 cheaper. The duplex even sold at a lower price per square foot than the $585,000 “fully-renovated with designer upgrades” 1955 four-bedroom across the street.
The same math could work here, if we would let it
The experience of cities like Portland, Durham, and Raleigh shows that in the real world, zoning that encourages small houses on small lots also results in small price tags. They have quickly cut the cost of new houses by hundreds of thousands of dollars, putting new houses in close-in, transit-rich neighborhoods within reach of middle-income and even moderate-income households.
The effects are clear in Arlington, where courtroom battles over the “Expanded Housing Choices” zoning reform have resulted in a few projects moving forward and others reverting to conventional teardowns. The first new duplex units to deliver under the new zoning are priced a full one million dollars less than new detached houses on sites where developers had pursued attached houses.
These cities have found that small lot houses cumulatively save local residents millions of dollars, make existing housing subsidies go further, do not threaten “neighborhood character” with additional demolitions, and cost local governments almost nothing extra. These homes’ lower prices make them more resilient to interest rates.
Instead, Greater Washington’s jurisdictions have deemed the vast majority of the region’s neighborhoods off-limits to small lots and small houses. Instead of listening to a handful of “supply skeptics” who refuse to believe that homebuilders will sell less land for less money, our local governments should make better choices and legalize more housing choices in more neighborhoods.
Top image: Three small new houses share what was one lot in Durham, North Carolina. They all sold for less than $300,000 in 2023. Photo by the author.