Op-Ed: How ADUs Can Ease the Housing Crunch

In an op-ed in Governing, Emily Hamilton outlines the results of her research into how accessory dwelling units (ADUs) can play a role in easing the housing crisis and the policies cities and states can leverage to encourage ADU construction.

“At one end of the spectrum, California policymakers have gone the farthest to protect homeowners’ right to build ADUs. On the other, New Hampshire policymakers legalized ADUs but left open the opportunity for local zoning ordinances to put many limits on them,” Hamilton explains. Even in California, owner occupancy requirements limited ADU construction until 2017, when a series of state laws limited the power of cities to regulate ADUs and led to an “impressive surge” in ADU permits.

Regulations and policies aren’t the only things that have an impact on ADU production, however. “Two other key determinants of ADU construction — and of its potential to lower prices in a given city or neighborhood — are how easy it is to adapt the existing housing stock to include them and the willingness of local homeowners to take the leap to build them.” Hamilton adds that in New Hampshire, where localities have a lot of leeway in restricting ADUs, some cities are seeing a high rate of permitting in part due to the state’s older population and the adaptability of existing housing stock.

Hamilton concludes that, with the right policies in place, ADUs “may be the least contentious way to create opportunities for more housing within existing residential neighborhoods.”