Eastampton already had more affordable housing units than required under New Jersey law.

By that reckoning, the township land-use board last year denied a request by the nonprofit Homes of Hope for an exception to build two multifamily duplexes in a neighborhood zoned for single-family homes.

But a three-judge appeals panel yesterday ruled that a town can't turn away low-income development even after it has fulfilled its state requirement, noting that affordable housing promotes the general welfare and warrants the type of exception sought by Homes of Hope.

The decision upheld a 2008 trial court ruling in Burlington County, where the precedent was set for the state's affordable housing regulations.

Municipal obligations to provide affordable housing, which originated from court decisions involving Mount Laurel in the 1970s and '80s, are being contested across New Jersey. The most recent mandate by the state, issued last year, calls for 115,000 units to be built over the next decade.

The affordable-housing advocates involved in the Eastampton case said that figure should be considered a minimum.

Homes of Hope president Kent Pipes said the ruling sent a "strong message" that towns would not get relief from the courts even after meeting their affordable-housing obligations under the state's Fair Share Housing Act.

"Even when a town has done what" the state Council on Affordable Housing "says it has to do," Pipes said, "somebody who wants to build affordable housing has the right to build more."

The courts have long held that affordable housing serves the general welfare and is an "inherently beneficial use," similar to hospitals and schools.

Homes of Hope proposed constructing two units on each side of an existing four-unit building not previously designated as low-income housing. The organization wanted to deed-restrict all eight units as affordable housing.

To obtain a variance to build there, the Burlington County nonprofit's proposal had to meet two requirements under New Jersey law: It had to improve the general welfare, and it could not negatively impact the public good or the intent of the zoning.

Homes of Hope argued that its proposal was an "inherently beneficial use," but Eastampton countered that affordable housing no longer fell under that favorable status in the township. The municipality cited a determination by the state that a 100-unit low-income family rental development had provided Eastampton 21 units more than it needed to meet its affordable-housing obligation for the period of 1999 to 2014.

Homes of Hope sued the township in February 2008, less than a week after the land-use board denied its request.

In a Superior Court decision last year, Judge John Sweeney noted that the court rulings that spurred the state's affordable housing regulations did not intend for each town only to meet the needs of the homeless within its own boundaries, but rather to contribute to the needs of the entire state.

Eastampton appealed, and arguments were heard in April. Chris Norman, an attorney for the township, said yesterday that he was not sure if Eastampton would appeal the ruling.

Norman said the decision undercut a message by the state that once towns meet their affordable-housing obligations, they would control their own destiny.

"It's sort of like 'no good deed goes unpunished,' " he said.

The decision was "extremely important," said lawyer Carl Bisgaier, who represents the Cherry Hill-based Fair Share Housing Center and argued before the appeals court in favor of Homes of Hope.

"It puts to bed an effort that's been going on throughout the state to undermine the statutory means by which a lot of affordable housing has been provided in the state, and that is through the use variance method," he said.