Takeaways
- New research shows that allowing for fully flexible parking could lead to more new homes—more than other land use reforms combined.
- According to new modeling research out of Colorado, fully flexible parking resulted in two to three times as many new homes as legalizing granny flats or larger multifamily buildings near transit, even when every new building still included some amount of parking.
- When given the option to maximize housing projects for actual housing instead of parking, buildings ultimately get more homes, become more financially feasible, and have a better chance of actually getting built.
Making parking fully flexible could unlock more new homes than other land use reforms combined, according to new research out of Colorado that modeled how multiple policies would impact economic feasibility for new housing projects.
The findings add to a growing body of evidence that making off-street parking optional is a small policy change that can lead to an abundance of new homes. Even though all the buildings modeled in the analysis voluntarily included parking, allowing homebuilders to create less parking made the biggest difference. In fact, building at lower home-to-parking-space ratios than what Colorado cities currently require could result in 40 to 70 percent more homes than are feasible to build today, the study found.
“Requiring more parking than the market demands leads to inefficient outcomes,” researcher Ian Carlton explained. “Excess parking takes up space in buildings that could otherwise be housing, adds costs that are seldom offset by revenues, and can determine whether certain types of housing projects fit on sites of various sizes. [Real estate modeling group] MapCraft’s pro forma evaluations capture all three of these factors.”
Compared to other zoning reforms such as legalizing ADUs or increasing building heights near transit, parking reform proved to be two to three times more effective at boosting housing supply.
Lower parking ratios increase homebuilding more than legalizing both granny flats and apartments near transit
The analysis, done by ECOnorthwest and MapCraft, looked at 19 counties across Colorado, representing about 90 percent of the state population and where nearly all future population growth is projected to occur. To estimate outcomes under different policy options, MapCraft generated potential development opportunities on eligible parcels and then found what would be competitive under current market conditions.
The 86-page report takes a deep dive into the outcomes of different combinations of housing policies. (Spoiler: more reforms = more housing.) But what caught our eye was one finding that compared eliminating parking mandates by itself against two other pro-housing reforms.
- Accessory dwelling units (ADUs) allowed one backyard cottage per property without additional utility fees or owner occupancy requirements. The analysis assumed one parking space per ADU, unless local governments required more.
- Transit-oriented development (TOD) would allow multifamily housing within a half-mile of rail and bus rapid transit stations and within a quarter-mile of bus routes with 15-minute service or better. Both existing and planned transit were taken into account, and local parking minimums were not adjusted for this scenario.
- Parking, under the fully flexible parking policy, was still incorporated into new buildings at a rate of one parking space for every two homes in transit-oriented areas and one parking space per home in all other areas. Those ratios were based on real-world findings from Seattle after the city relaxed parking mandates in 2012. These results were compared to current local parking minimums in the baseline model.
If state legislators had to pick just one of these to throw their weight behind, the winner was clear: Fully flexible parking would result in more new homes than legalizing granny flats and larger multifamily buildings near transit combined, even if every new building still included some amount of parking.
When considering the policy influence along transit routes, increasing the allowed building size would be only a fraction as effective as allowing flexible parking quantities for what’s already legal under zoning today.
Over a wider geography, parking reform still came out as the most effective policy for homebuilding. And that’s when every new apartment outside the transit zones still built one parking space for every home.
The increase in potential homes was primarily driven by already-feasible multifamily buildings increasing the number of apartments beyond what existing parking ratios would have allowed. “A small number of projects make the majority of the impact,” Carlton said.
Sightline has reported on builders around the Pacific Northwest doing just that. After parking mandates were eliminated in Beaverton, Oregon, local architect Gene Templeton redesigned his small apartment building to create 13 homes instead of 9. In Bellingham, Washington, the first new building permitted since mandates were repealed in Old Town, now unconstrained by the size of the parking lot, was designed with twice as many homes than would have been allowed before.
Larger studies from Buffalo and Seattle after parking mandates were relaxed found that parking reform had a wide impact on the housing market. They showed that 60 to 70 percent of new homes in multifamily buildings ended up using the new flexibility, with those buildings providing more homes per parking space than previously allowed.
The study suggests that many buildings around Colorado might do the same if permitted to. When given the option to maximize housing projects for actual housing instead of parking, buildings ultimately get more homes, become more financially feasible, and have a better chance of actually getting built. The research unveils a simple yet powerful truth: to unlock more homes for all our neighbors, the most effective policy is simply to allow less pavement.
Read the full analysis here.
