As the Bay Area’s housing crisis continues to escalate, cities like Petaluma are just not building homes fast enough to keep up with demand that is driving housing prices sky high. If construction of new homes can’t keep pace with demand, perhaps modifying the lots of existing homes will help ease the crunch.

Petaluma is finally getting around to modifying its policy on so called “granny” units to bring it in line with new state laws. Granny units are secondary living spaces adjacent to a main house, also known as accessory dwelling units.

Construction of granny units could open up a wide swath of low income housing options for Petaluma residents. But until now, a significant level of red tape has deterred homeowners from building these additions; an average of only five such units are built in Petaluma each year.

Several state laws passed last year require local jurisdictions to ease restrictions on the creation of secondary units, and thus encourage their development. Sonoma County in January brought its building code in line with the new state laws, and Santa Rosa followed suit in March.

Now it is Petaluma’s turn. The city’s planning commission recently took the first stab at crafting an ordinance to facilitate more granny units. The current proposal would increase the allowable size from 640 to 720 square feet, while concurrently easing parking requirements.

The proposed changes would also require that granny units are rented for at least 30 consecutive days, a policy aimed at deterring people from renting these units on short-term vacation rental websites like Airbnb. After all, it would be no help to the housing crisis to build dozens of granny units in Petaluma, only to see them filled with weekend tourists.

If the city is planning to enforce this aspect of the granny unit policy, it must also do a better job of enforcing its current short-term vacation rental ordinance. Residents who put their homes up for rent on sites like Airbnb are required to register with the city and pay hotel taxes like other lodging establishments. However, an audit revealed that only a fraction of Petaluma’s vacation rental hosts are complying with the law.

One shortcoming of Petaluma’s newly proposed granny unit policy is to limit such dwellings to structures with foundations. That would preclude the development of so-called tiny houses which have soared in popularity recently.

Santa Rosa’s granny unit policy specifically allows foundationless dwellings, with an eye to encouraging tiny houses. Sonoma County is even more forward looking on tiny houses. The board of supervisors recently approved a tiny house pilot project for homeless veterans that is one of the first in the nation to use government-owned land to create these dwellings.

Petaluma, with at least one tiny house developer, is ripe for including these structures in its housing mix.

The city council will have the final say on Petaluma’s newly revised granny unit policy in July. We encourage council members to adopt a robust policy that maximizes opportunities for creating new affordable housing for Petaluma’s low and middle-income residents, including young families, who are being priced out of their community.