Habitat for Humanity International isn’t building as much new habitat as it used to.

Facing rising land prices, the 38-year-old charity, which provides homes for low-income families, is placing more emphasis on buying and renovating existing homes in the U.S.

The number of homes Habitat renovated in the U.S. more than doubled to 1,435 in its 2014 fiscal year that ended June 30 from 2008, according to the group. New construction, meanwhile, declined 31%, to 3,323, in 2014 from 2008.

The main culprit: land prices, which have increased at double-digit percentages since 2012, making building more expensive. A typical Habitat home has three bedrooms and sells for an average of $80,000 to $100,000, regardless of whether it was built from the ground up or renovated.

“The biggest part is land,” said Habitat Chief Executive Officer Jonathan Reckford. “If we can’t get it donated, we have to buy land. And that becomes a big part of the cost.”