Planning for Success
Accessory Dwelling Units
ASSOCIATES INC
Continue to Integrate Accessory Dwelling Units
Issues /Opportunities Addressed: C)
Timeframe for Action: Short Term
An accessory dwelling unit (ADU) is an independent residential living area
that is on the same property as a larger, primary dwelling unit. The term
“accessory” is purposely meant to describe the unit as secondary to the
primary unit, in the same way a garage is of secondary importance to the
home. These units cannot be sold separately and are typically limited in size
to help reduce impacts on neighbors and blend in with surrounding homes.
These units can help meet a wide range of living arrangements, provide an
affordable housing option to family or friends, or create an opportunity for
the primary homeowner to generate additional income through rent.
An accessory dwelling unit generally takes three forms:
1. Re-purposed space: e.g. above the garage or in the basement.
2. Stand-alone unit: separate from the primary home.
3. Attached: addition to the primary home.
ADUs in Nashua could play an important role in the City’s overall housing
stock based on what we know from the demographic and market data:
¢ ADUs offer an affordable housing option for smaller households
¢ ADUs could provide seniors, especially those living alone, with another
housing option and allows older owners to age in place
¢ ADUs could also provide a lower cost housing option for younger
residents
¢ ADUs more easily integrate multi-generational households to live together
in the same structure or on the same property
¢ ADUs offer a quick and easy way to boost housing production
Nashua Housing Study - 59
ADUs are allowed by law across the State of New Hampshire, therefore
Nashua must also allow them to comply with state statues. According to
City staff, the Planning Department sees on average one ADU application per
month and would likely see more but cost is the biggest hurdle for existing
homeowners. ADUs are allowed by Special Exception in Nashua, not by right,
which adds an additional layer of process, time, and money to getting your
approval.
In response, the City should consider the development of pre-approved ADU
plans that could more quickly and easily be permitted and constructed. This
would save time and money for the owner and City staff and boards. If
Nashua can establish pre-approved designs for ADUs, there could be an
opportunity to revisit the discussion around making ADUs by right instead of
through Special Exception. The City could make ADUs part of a city-wide
housing campaign to more widely introduce the concept, discuss the
benefits and drawbacks, show some local examples, and describe the
process for permitting and constructing an ADU.
The City might also consider reduced fees for ADUs compared to traditional
residential structures to encourage more units and reduce the cost barriers.
