A bill Gov. Chris Sununu signed into law last week is intended to make it a little easier to fill the growing need for new housing, but the measure’s sponsor says much more must be done to spur residential construction.

House Bill 1400, whose main sponsor was Rep. Rebecca McWilliams, will give municipalities greater authority to ease some zoning requirements and offer tax incentives for converting office buildings to residential use.

“This is a first step, and it’s a good first step,” McWilliams, D-Concord, said in an interview Tuesday.

“I think time will tell as we see the ripples of how this plays out in terms of conversion of office to residential and new development of multifamily housing on lots where that was not possible because of parking requirements.”

HB 1400 mandates that cities and towns cannot require more than 1.5 residential parking spaces per unit in multifamily developments of 10 units or more.

She said some municipalities have been requiring new apartment buildings to have more parking than what is actually needed.

“So you have a lot of excess asphalt, which is not great for the environment,” she said. “Also, the size of two parking spaces together is the same size as a studio apartment, so you’re taking up a footprint in a large development that could potentially be used for more units.”

Also under the bill, communities can grant property tax relief for up to 20 years for office buildings that are converted to residential use.

“In our larger population centers, there are commercial properties that can’t be converted now because of the tax implications, so this opens that up as a new window to do that conversion,” McWilliams said.

She said the bill is only a first step because cities and towns in wide swaths of the state continue to have exclusionary zoning practices, such as allowing residential construction only on large lots.

This drives up the cost of such homes, making them unaffordable to most people, including people in industries providing services to people who move into those homes, McWilliams said.

“This is a state problem that needs to be fixed with state solutions,” she said. “I don’t expect that we’re going to be able to solve our housing shortage at the individual town level.

“It’s taken 50 years for this patchwork quilt of zoning to be established and expecting each municipality to individually change their zoning to become more housing friendly in the next 10 years is unrealistic.”

A 2023 report from N.H. Housing estimated the current housing shortage at 23,670 units.

The organization’s 2024 Residential Rental Cost Survey found that the statewide median monthly gross rent for a typical two-bedroom apartment with utilities was $1,833, a 36 percent increase from five years ago.

In Cheshire County, that same apartment would be $1,455, a 30 percent increase from five years ago.