PITTSFIELD — Do you need help funding an accessory dwelling unit? You can now apply for a low-interest, 20-year $250,000 loan for one.

Gov. Maura Healey has officially launched the ADU financing program meant to help residents clear one of the big hurdles of building these units.

The program, which was first announced in December, is another form of support the Healey administration is giving to ADUs, which are separate in-law suites that it sees as a way to open up additional housing in the state.

Berkshire County only saw six permit applications over the first six months of the ADUs being allowed by right, and local officials pointed to the high costs to permit, design and build the units as one of the main reasons for that dearth of applications.

Massachusetts launched a program to help homeowners financing the construction of accessory dwelling units. Through MassHousing, qualified homeowners can take out lower-interest loans, up to $250,000 for detached units and $150,000 for attached ones.

This program, which is being administered by MassHousing, an independent, quasi-public agency that supports affordable housing opportunities, aims to help relieve some of that burden by offering below market-rate interest on the second mortgage.

"Accessory dwelling units are one of the most practical ways to create housing and drive down costs in communities across our state," Healey said. "Now we’re partnering with MassHousing to help more homeowners actually build them."

The maximum loan allotment of $250,000 is for detached ADUs, with attached units being eligible for loans up to $150,000. The loans are interest-bearing, but because of the funding structure, MassHousing brought the interest rate down to a fixed 5.25 percent over the 20-year term.

The average interest rate for a 30-year loan is 6.11 percent, and the average for a 15-year loan is 5.5 percent, according to Freddie Mac.

MassHousing is using $20 million it was previously awarded for "mission-oriented activities" to fund the program. However, the ADU loans will be dispersed and managed by qualified lenders. For Berkshire County, those lenders are Greylock Federal Credit Union, Monson Savings Bank and BankESB.

Homeowners looking to apply for this loan cannot make more than 135 percent of the area median income. For a family of four in Pittsfield to qualify, they would have to make less than $140,000.

The accessory dwelling unit loan program is one of three ADU-related programs announced this past December. The trio of programs is meant to support homeowners in every step of the ADU building process.

Before applying for one of these loans, homeowners must have design plans, the appropriate permits and anything else they need to begin construction.

To help with the pre-construction process, the state held an ADU design challenge, with all the winning designs being made publicly available.

The state also allocated $10 million to support a technical assistance program, which will help educate homeowners and provide support in the predevelopment and construction process.

The state views the three programs as a way to support homeowners every step of the process of building an ADU.

"Our goal is to make ADUs a real option for more homeowners, not just those with significant equity," said Jennifer Maddox, the interim secretary for the Executive Office of Housing and Livable Communities. "By expanding access to affordable financing, we’re helping more residents take advantage of the new law to expand their housing options."