PROVINCETOWN — Spend enough time learning about Cape Cod’s housing crisis and you’ll eventually hear something about ADUs, or accessory dwelling units. By definition, an ADU is a smaller residential unit, usually a one-bedroom or studio apartment, that can be legally added to a single-family home. Because Cape Cod’s existing housing is overwhelmingly composed of single-family homes, ADUs are sometimes described as an ideal solution for the Cape, a potential route to hundreds or thousands of smaller new places for people to live.
The theoretical promise of ADUs has been in stark contrast to their reality, however. All 15 towns on Cape Cod now permit some kind of ADU in their zoning bylaws, yet very few have been built.
Brewster and Falmouth have had more success than their neighbors and have each permitted more than 20 ADUs over the last few years. In most other Outer and Lower Cape towns, however, you can count the number of ADUs on one hand.
The ADU Resource Center, a joint project of the Community Development Partnership (CDP) and the Homeless Prevention Council, was created last April to help homeowners in the eight Lower and Outer Cape towns with permitting and building new units. It was funded with a $1-million earmark that state Rep. Sarah Peake attached to a spending bill in November 2021.
The Resource Center offers free guidance to homeowners at every step of the process, especially when it comes to understanding what their town’s zoning rules might permit them to build and what it might cost. The Resource Center can also provide a $10,000 forgivable loan, which can be paired with other assistance from the Housing Assistance Corporation of Cape Cod, the Cape Light Compact, and even some individual town programs, said Andrea Aldana, chief program officer at the CDP.
Terri Barron, who oversees the Resource Center, described some of the obstacles that the center can help with — and some that it can’t.
“We do a feasibility study of the property for free, in which we go over all the rules that will apply to them, including lot coverage, square footage, and septic,” said Barron. But the rules might require an actual site survey, which can cost $5,000.
State and town regulations on septic systems often stop homeowners in their tracks, Barron said. The state’s Title 5 septic rules limit the number of bedrooms per acre regardless of other zoning requirements, Barron said. New construction can trigger town rules about septic system upgrades, which can cost $30,000 or more.
Then there is the cost of an architect — “usually $3,000 to $5,000,” Barron said — and the time to go through planning or zoning boards.
According to the Cape Cod Commission, nearly every town permits some kind of ADU configuration by right — but in Barron’s experience it’s usually not so easy.
“For very few people has it been a straightforward slam dunk like that,” Barron said. If any circumstance doesn’t fit the bylaw, then homeowners have to ask their planning or zoning board for a special permit, which can take months.
Construction costs are the ultimate obstacle, Barron said, with an average cost around $450 per square foot. For an 800-square-foot ADU, that’s about $360,000.
There are financing options, Barron said, and many people can pull money out of their existing house with a home-equity loan. But depending on interest rates, the rental income from the ADU might not be enough to cover the new loan.
Of the 64 homeowners who have contacted the Resource Center this year, only about 10 appear likely to finish the permitting process and actually build an ADU, Barron said. Most of them have specific reasons to want the extra unit — typically, either adult children or elderly parents are moving in.
“We have some people who just want to help with the housing crisis” and create a rental unit, Barron said, but they’re more likely to be deterred by the high costs and long process.
“We think $50,000 would be enough of an incentive to unlock some of that larger second pool of people who don’t have family reasons but are interested in building,” Aldana said. “But that means that ADUs would be both time-intensive and resource-intensive, and at that point I think a wider conversation is warranted.”
Compared to the recent past, three new ADUs per town per year would be a big improvement — and yet still completely dwarfed by the scale of the crisis. A study commissioned by the Housing Assistance Corp. last fall predicted that 829 households earning less than $100,000 per year would be displaced from Cape Cod this year.
“Each unit is valuable, but these towns need lots of units,” Aldana said. “The strategies that will get us there are having multifamily zoning by right in village centers, having towns release their technicalities around how bedrooms are configured on a site, and allowing maximum residential density as long as wastewater regulations and environmental protections are followed.”
In most residential parts of Cape Cod, a four-bedroom house would be legal; a three-bedroom house and a one-bedroom ADU might be legal; and a duplex consisting of two two-bedroom units would be forbidden. State wastewater laws control how many bedrooms are allowed, Aldana said — but whether they are in a single-family home, a house with an ADU, or a duplex is entirely up to the towns and their zoning choices.
“We don’t need to put dense residential development everywhere,” Aldana said, “but we do need to concentrate development in village centers that have more amenities, better infrastructure, are more walkable, and are better for the climate.
“We can do this in a beautiful way, with good design and open space,” Aldana added. “This is still very controversial in most of the towns. But you’re never going to get the number of units with ADUs that you’ll get from these larger-scale developments.”