A new law aims to make it easier for homeowners with existing structures on their property to convert them into accessory dwellings units. The units are sometimes called in-law suites or basement apartments, and many housing advocates have supported these efforts to increase housing stock.
Sponsored by Democratic Rep. Allan Howland of Durham, the law adds to the legislature’s expansion of ADU development last year, which allowed property owners to convert or build the detached and attached buildings with minimal red-tape. Historically, some municipalities would require homeowners to meet certain conditions or get a zoning variance, or exception, to convert an existing structure or build a new one into an ADU.
But even with last year’s ADU-friendly laws, Howland said constituents told him their towns were still telling them to go before the local zoning boards before getting a building permit for their ADU project.
“The town planner is saying, ‘Oh, no,’ you have a non-conforming property,” Howland said. “That garage met all of our rules, [but] it doesn't meet our rules anymore.”
A non-conforming structure is one that was up to current zoning requirements when it was built, but isn’t anymore. In these cases, Howland said, a constituent’s decades-old garage may have once been allowed to be six feet from a property line, but the town updated its zoning requirements years later, so it now has to be 10 feet away.
“So in order for you to build that ADU, you're going to have to go to the Zoning Board of Adjustments,” to get a waiver, or a variance, Howland said. “That adds time, hassle and cost.”
The new law makes it so property owners with structures built before July 1, 2025 are exempted from getting a zoning variance if their structure is nonconforming. Howland said this will streamline the ADU permitting process, allowing more people to build much-need housing units around the state. Structures built after July 1, 2025 will be protected from future zoning changes if they meet development and completion standards under an existing law.
Robert Quinn, the CEO of the New Hampshire Association of Realtors, supports ADU construction, but he said the law is redundant because municipalities shouldn’t be requiring extra steps when homeowners convert their nonconforming properties into ADUs.
“We believe the legislature had already provided municipalities with clear guidance on how accessory dwelling units could be sited and approved,” Quinn said. “And we didn't think that House Bill 1079 added meaningful clarity to existing law.”
Quinn is also concerned that the law’s distinction between structures built before or after July 1, 2025 could confuse property owners about what they need to do when they explore developing an ADU.
“Is a property owner going to understand this? Does that misunderstanding lead to lawsuits? Will towns misinterpret it?”
The New Hampshire Municipal Association also opposed the bill, saying its language for future ADU permitting could be confusing for municipalities trying to enforce zoning regulations.
Quinn said he understands the bill is meant to give immediate help for certain property owners in municipalities, but hopes it won’t further muddy the waters for future ADU construction.
