Free apartments hidden inside mostly empty houses

The uncarved block

There are thousands of existing housing units that are only partially used. Imagine, for example, a family where the children have grown and left but the parents remain in their 3,000+ square foot, 4-bedroom home. The parents may not wish or may not be able to maintain such a large home but are forced by the existing zoning to make a binary decision: either stay or leave. There is no apparent middle-ground, and frequently the owners stay well past the time they can care for the property, leaving a great portion of their home vacant, and in some cases in a declining state of repair.

This is why we often see properties listed for sale that have been owned for 30+ years but in a deteriorated condition that only a developer could consider taking on. That situation creates a triple loss to our community:

1. Owner: The owner loses the rent they would collect if they could carve out another unit and remain in their home (or the space for a potential caregiver so they can remain in their home), and they lose money on the eventual sale if the home deteriorates in the meantime.
2. Residents: A potential housing unit that would be suitable for the middle-market is left mostly empty. Residents lose because this reduction in supply helps drive up the cost of housing generally.
3. Workforce: If the condition of the house has deteriorated, then when the house is eventually sold the only way the numbers work for the developer, given our strict zoning, is to build large luxury units instead of more modest housing. This further reduces the supply of workforce housing.

Brookline Warrant Article 19 from December 2020 Town Meeting, which passed, is a commendable attempt to address this issue.¹ Is it too modest? It would allow owners of single-family homes to create an “accessory dwelling unit,” i.e. a small apartment in their home. There are notable restrictions including:

• Not allowed in new construction. The house must be at least five years old.
• Not allowed in condos, even if it’s a large townhouse. Only allowed in single family houses.
• Cannot be separately sold. The owner must own the whole house.
• The house must be owner occupied. The owner can live in either the main house or the accessory unit.
• Must be small. By right, whichever is less: 30% of the house or 750 square feet. Special permit up to 950 square feet.
• No short-term rentals allowed. Minimum 6-month rental terms.

Questions to consider to improve the proposal:

1) Why prohibit accessory units in new construction? Could this be a rare opportunity to create affordable housing units willingly subsidized, supported, and maintained by wealthy property owners? Consider that most new construction (or gut renovations) are for high-end luxury housing and are not financially attainable to most of our population. An accessory unit in that house, however, would be. It would add utility to the home for the owner, add value to our tax base, and create affordable workforce housing – a potential win-win-win. Would there also be a social benefit by integrating people from different levels of income into the same housing? Also, wouldn’t these be much more cost effective to build at the time of the home’s construction rather than five years later? Limiting this option to homes that are at least five years old will dissuade a number of people who would otherwise consider it.

2) Why restrict this option to a classification (single family house) instead of by a physical constraint? Imagine a large townhouse. Some are classified as an “attached” single family, while others as condominiums. The distinction is legal, not physical. If the town allows accessory units to be built in some properties, then wouldn’t it be unfair to prohibit it in similar properties just because the ownership is structured differently? This is a decision that would be best left to the individual condo associations, not the town. There are many condos that could be suitable in their size or layout, and where the owners face the same challenges and incentives. I count 436 condos in Brookline with at least 2,500 square feet and that therefore would be large enough to qualify for the maximum by right 750 square foot accessory dwelling units. (There are thousands more that would qualify for smaller units).

3) Why limit Accessory Dwelling Units to such a small size? Why limit a house of 5000 square feet to the same 750 square foot ADU as a home of 2500 square feet. If we look to our neighbors in Newton, they allow ADUs of least 250 square feet up to a maximum of 1,200 square feet for internal units by special permit, or 40% of the total building size.²

4) If we want to add more housing, would a practical next proposal be to change the zoning to allow the 4,734 single-family houses in Brookline to convert to true two-family houses? Brookline, especially zip codes 02445 and 02446, is already dense with a mix of housing types, and it’s part of what makes our town awesome. As long as no one is compelled to convert their house it seems like a win-win: the owners of single-family houses would instantly increase the value of their property, the town would increase its tax base, the supply of housing would increase as a number of single-family houses are turned into two-family houses, and our ecological footprint would be reduced.

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