Navigating New Hampshire’s New Accessory Apartment Law

A new state law that will take effect June 1, 2017 limits municipalities’ ability to enact zoning and land use regulations that prohibit or restrict “accessory dwelling units” (also called “accessory apartments”).

Senate Bill 146, which Gov. Maggie Hassan signed in March, added three new sections to RSA 674 – sections 71, 72, and 73 – and removed the ability of municipalities to regulate accessory dwelling units as an “innovative land use control” under RSA 674:21.

Before we discuss the substance of SB146, it’s important to discuss the bill in its economic context.  In 2015, the late economist Dennis Delay confirmed what many residents in New Hampshire had suspected for years: New Hampshire is an aging state with low population growth whose land-use regulations were not well-suited to address the downward trend in population. As Delay said at the New Hampshire Center for Public Policy Studies in September 2015, “We have a set of zoning, planning board and land-use ordinances that were designed to cope with population growth of 10,000 to 20,000 a year, but ill-serve the New Hampshire of today. There has to be a serious look at housing policy and its impact on economic development.”

Speaking on New Hampshire Public Radio’s The Exchange, economist Russell Thibeault corroborated Delay’s statement, noting that “a lot of [millennials] simply can’t afford housing despite exceptionally low interest rates.” Thibeault said migration into New Hampshire from other states is also stagnant, due to New Hampshire’s high median housing prices.

The high cost of housing in New Hampshire is not limited to home ownership. Thibeault noted that despite the decrease in housing prices during the recession, “rents didn’t drop at all. Vacancy rates among rental units now are around two percent, which the industry standard is five. So there aren’t many units out there, and they are more expensive.”

The NH Legislature enacted SB 146 due to its express findings that there is a “growing need for more diverse affordable housing opportunities” in New Hampshire and that accessory dwelling units provide important benefits, by offering housing opportunities to millennials and college graduates “saddled with significant student loan debt,” as well as elderly and disabled residents.

What Is an Accessory Dwelling Unit?

SB 146 defines an “accessory dwelling unit” as a “residential living unit that is within or attached to a single-family dwelling, and that provides independent living facilities for one or more persons, including provisions for sleeping, eating, cooking, and sanitation on the same parcel of land as the principal dwelling unit it accompanies.” In other words, an accessory dwelling unit is a unit separate and distinct from a primary dwelling unit that has its own kitchen, bathroom, and a place to sleep. It can be attached to the primary residence, or, if the municipality allows it, an accessory dwelling unit can be a detached, separate structure.

How Can Municipalities Regulate Accessory Dwelling Units?

Under SB 146, in all zoning districts that allow single-family dwellings, municipalities must allow accessory dwelling units as a “matter of right” (no zoning approval necessary) by special exception (issued by a zoning board of adjustment), or by conditional use permit (issued by a planning board). In the absence of any provision regarding accessory dwelling units, one accessory dwelling unit shall be permitted as a matter of right to any single-family dwelling, and only a building permit shall be required, if necessary. Homeowners can have an accessory dwelling unit without the need to comply with any additional requirements for lot size, frontage, space limitations, or other controls beyond what is otherwise required for a single-family dwelling, except that municipalities can require larger lot size if the accessory apartment is detached from the primary residence.

Municipalities are prevented from requiring that a familial relationship exist between occupants of the accessory dwelling unit and the primary dwelling unit. Although SB146 requires that an internal door separate the accessory dwelling unit from the primary dwelling unit, municipalities cannot require that door to remain unlocked – presumably a tactic to prevent renting accessory apartments to non-relatives. Additionally, municipalities cannot limit accessory apartments to just one bedroom; (the bill is silent as to whether a municipality can limit accessory apartments to two bedrooms).

Accessory dwelling units must be permitted to some degree, whether as a matter of right or through other land-use approval, but homeowners are not free to construct them without zoning restrictions or other regulations. As stated above, municipalities can require a homeowner to obtain a conditional use permit or a special exception prior to constructing an accessory dwelling unit (SB 146 does not squarely address the permissibility of special exception or conditional use standards that could be implemented by municipalities other than the express authorizations and prohibitions stated in the bill). Homeowners must continue to comply with lot coverage standards and maximum-occupancy-per-bedroom standards. Also, when seeking a permit to construct an accessory apartment, the applicant must make adequate provisions for water supply and sewer disposal; although, a separate system shall not be required.

Additionally, municipalities can limit the number of accessory apartments per lot to no more than one and require that a homeowner demonstrate that the primary dwelling or the accessory apartment is the homeowner’s primary place of residence (although the municipality cannot specify which unit the homeowner must occupy). Municipalities may enact provisions to ensure that the accessory unit has adequate parking and can establish standards for maintaining the “aesthetic continuity with the principal dwelling.” Municipalities can also enact minimum and maximum sizes for accessory dwelling units, provided that municipalities cannot restrict the accessory dwelling units’ size to less than 750 square feet.

In summary, SB 146, once it goes into effect, will limit what is now the relatively broad authority of municipalities to regulate accessory apartments. The bill was specifically enacted to refocus the purpose of zoning and land use regulations from controlling or limiting population growth to promoting and encouraging young people and migrants to relocate to, or remain in, New Hampshire.