ROCKLAND — The Harrison family moved into their brand-spanking-new home on Sunday, courtesy of the Midcoast Habitat for Humanity. The volunteer organization has now built five homes in five years in the city, and turned them over to low-income families.

Working nights and weekends, Harrison, a mechanic for George Hall, worked hundreds of hours of “sweat equity” to build the new house for his wife and their six children, ages 1 to 13.

He got assistance from 29 Habitat volunteers, mostly retirees, including several doctors, a Navy veteran, chemist, aircraft engineer, pilot, clergyman, yacht captain and business executive who showed up all through the winter for the Tuesday, Thursday and Saturday work sessions.

Numerous contractors and suppliers contributed labor and supplies for the project.

One of the hardest-working volunteers was neighbor Stephen Erickson, who moved into a Habitat-constructed house last year.

Bob Appleby of Hope, a former DuPont chemist, decided to volunteer after he saw a picture of former President Jimmy Carter in overalls, building a Habitat structure in Atlanta.

Retired airline pilot Hub Schleicher of St. George learned about the organization from a friend and decided to volunteer.

Retired physician Dr. Jaap Vrolijk loves to see the children come to the building site “to see where their room is going to be.”

Yacht captain Frank Lawson of West Rockport has his boat in storage during the winter and decided that Habitat was “a good way to contribute to the well-being of mankind. I have a bit more time than I do money.”

The three-bedroom modified ranch home was designed by Peter Gross of Camden.

Midcoast Habitat is one of more than 1,000 affiliates of Habitat for Humanity International, which is dedicated to building homes for low-income families.

Crews of volunteers have built simple but sturdy homes for families who otherwise could not afford homes of their own. Families purchase their new homes through mortgage payments on noninterest loans and their own labor.

Habitat spokesman Norman Weeks said Habitat houses “have given fresh hope and dignity to hard-working midcoast families for whom the cherished American dream of home ownership has appeared out of reach. Moving to a home of their own, sometimes from incredibly wretched conditions, has been especially beneficial for the children involved. None of this would have been possible without our volunteers and the hundreds who have dug down deep to contribute.”