MADISON, Wis. -

Habitat for Humanity of Dane County has reached a milestone and is celebrating the construction of its 250th home.

For 28 years, the organization has been dedicated to building affordable homes for low-income families in Madison, Fitchburg, Sun Prairie and Oregon.

Habitat for Humanity makes houses affordable by giving families a mortgage with no interest rate and capping their payment at 25 percent.

Homeowners still pay the full price for their house.

Families have to earn less than 60 percent of the Dane County median income to be eligible for the program.

For a family of four, the family would have to earn between $25,000 and $48,000 to qualify.

Habitat for Humanity CEO Valerie Johnson said the need for affordable housing has significantly grown over the years.

"When we started in Dane County, we were building one or two houses a year, and it's been about the last 10 years that we've really scaled up. Now we're building 15 a year," Johnson said.

Families are required to spend at least 325 hours on the construction site to help build their house, and attend educational classes on home ownership.

The 250th home in Madison was given to a family of six who immigrated from Vietnam.