by Amy Dain, for Pioneer Institute of Public Policy Research and Smart Growth Alliance, July 2018 (This study updates a 2004-06 study on ADUs by the Pioneer Institute.)
Even in the midst of a housing crisis, zoning laws prohibit most homeowners in cities and towns around Boston from adding accessory dwelling units (ADUs) to their single family houses. An ADU is an apartment within or behind an own- er-occupied single family house that appears from the street to be a single-family as opposed to a two-family house.
Homeowner-voters can be reassured
that new rental hous-
ing that could be added as ADUs would be highly dispersed and barely visible.
The houses are owner-occupied; the land- lord
lives next to the ADU renters, so the risk of property-ne- glect or loud parties is
minimal. The houses also have to look like single family
houses. Since household sizes are shrinking, new residents in ADUs might maintain
population densities, but are
unlikely to increase them.
Moreover, ADUs are permitted at such low levels now — only 2.5 permits annually per municipality where they are allowed — that permitting levels could increase substantially without being at all noticeable in neighborhoods. If the region were to average five permits per municipality per year across 100 municipalities, over a decade, ADUs could provide 5,000 apartments, dispersed among 538,000 single family houses. Less than one in 100 houses would have an ADU, yet the new rentals would house thousands of people.
To solve the extraordinarily large deficit in housing for the greater Boston region, over 180,000 units of new housing should come on line in the next few years. This deficit is the result of a rapid expansion in in-migration due to new job creation, with no commensurate increase in housing production for the people taking those new jobs.
The report concludes that zoning is a primary culprit in restricting the development of an adequate housing supply, creating a “PAPER WALL” keeping out newcomers. The cost of this inadequate supply is a huge demand for housing which, in turn, bids up the price for available housing. The following “culprits” are considered: inadequate land area zoned for multi-family housing; low density zoning; age restrictions and bedroom restrictions; excessive parking requirements; mixed use requirements and approval processes. Alternative zoning models are suggested.
Elements such as “Approval Process”, “Mixed Use”, “Village Centers vs Isolated Parcels” and “Building Up or Building Out” are considered.
Researcher Amy Dain reports on two years of research into the regulations, plans and permits in the 100 cities and towns surrounding Boston. The research was commissioned by the Massachusetts Smart Growth Alliance and funded collaboratively with: Citizens’ Housing and Planning Association, Home Builders & Remodelers Association of Massachusetts, Massachusetts Association of Realtors, Massachusetts Housing Partnership, MassHousing, and Metropolitan Area Planning Council.