East Hampton and Riverhead to spur more accessory apartments to boost affordable housing

Two East End towns are taking steps to spur new accessory apartments in the hopes of alleviating the region's affordable housing crisis.

East Hampton is weighing a package of zone changes and financial incentives to encourage more accessory dwelling units, or ADUs, apartments that share property with a single-family home, either within the home or in a detached structure such as a garage.

The town is looking to eliminate a ban on second homeowners from creating ADUs. Officials also plan to lower minimum lot size requirements so more properties are eligible to build the apartments.

On Tuesday, the Town of Riverhead overhauled its ADU rules, streamlining the permitting process and abolishing the approval requirement of a review board. The new law increased the townwide cap of ADUs to 500.

In East Hampton, ADUs can be up to two bedrooms and between 300 and 1,200 square feet. In Riverhead, they can have no more than one bedroom and must be between 400 and 1,000 square feet. In both towns, ADUs cannot be used for short-term rentals.

Interest in ADUs has jumped on Long Island, Newsday has reported. For homeowners, the apartments can mean extra income or a separate living space for a family member.

In New York City, Mayor Zohran Mamdani plans to launch tools to support ADU development. Some Long Island governments have rejected calls over worries about increased traffic and stress on public services.

Hamptons plan

East Hampton officials see ADUs as valuable for increasing housing stock on the South Fork, where home prices have climbed to record levels and affordable housing options are limited.

In East Hampton, ADUs are considered affordable housing and must be rented at or under prices established by the U.S. Department of Housing and Urban Development.

Requiring ADU builders to be primary residents has limited their construction. In East Hampton, many properties are used part-time and owned by limited liability companies.

“Enabling those properties to have year-round residents on them who can help the town and provide different services is a critical piece” to addressing the affordable housing shortage, Councilman Tom Flight, the bill’s sponsor, said during a town discussion on Tuesday.

The proposal would also reduce the minimum property size requirement from 20,000 square feet to 15,000. 

East Hampton has 50 ADUs, with 16 more in development, according to a recent housing study that used data collected last year. Town officials hope to raise that number toward its imposed caps: 40 per school district, and 200 townwide.

Councilwoman Cate Rogers, who said she generally supported the proposal, cautioned that allowing corporate owners to participate could open the door to abuse.

But other board members said there are safeguards in place. “We should not be stopping affordable housing being built because we're concerned about giving the money to someone who we think might be too rich to get it,” Flight said.

The town is also weighing financial incentives. Among those, one would offer a property tax exemption that phases in assessment increases from the construction of an ADU. The exemption would be for up to $200,000 and would depreciate and phase out after 10 years.

Another would create an interest-free loan program of up to $100,000 for homeowners who build new ADUs. The program would be bankrolled by the town’s Community Housing Fund.

Board members said they want to give the loans to full-time residents who cannot afford to build accessory apartments.

Housing Help Inc., a nonprofit, has encouraged Long Island governments to adopt pro-ADU policies. Pilar Moya-Mancera, the executive director, said East Hampton's efforts are “exactly the kinds of policy tools needed to unlock accessory dwelling units at scale."

Riverhead's overhaul

In Riverhead, the ADU permit process will now be handled entirely by the town's building department. Previously, a now-defunct review board oversaw the approval process.

The law increases the allowed maximum size of ADUs. The town continues to require that the principal dwelling unit of a property with an ADU be owner-occupied. There are around 130 ADUs in Riverhead Town, officials said.

Town officials said the policy change would increase affordable housing and relieve residents at both ends of the spectrum — from young adults living to aging parents who want to remain close to their families.

“It also gives those people that are maybe struggling with their mortgage payments the ability to help themselves and take in a tenant,” Councilwoman Denise Merrifield said in an interview Wednesday.