Bob Karlstrand, a Vietnam-era veteran with a heart as big as his house, lived long enough to meet the beneficiaries of a magnificent act of charity.

Karlstrand, 66, is dying of late-stage colon cancer.

In 2015, he agreed to donate his Maple Grove house to Twin Cities Habitat for Humanity. It promised to refurbish it after he was unable to live there and sell it at a discounted price to a veteran. Karlstrand is now in hospice care.

Earlier this month, U.S. Army veteran Bonita Reyna-Berg and her grandson, Isiah, 14, moved into the house Karlstrand acquired in 1976 and vacated last year. They will pay $1,025 in principal and interest monthly for a remodeled house that was appraised at $225,000. Habitat discounts the mortgage to the point where payments to cover it are no more than 30 percent of the owner's income. A grateful Reyna-Berg also worked alongside the crew that updated the house.

Karlstrand, who worked in the insurance industry, couldn't say much recently. He still has a radiant smile.

"I've got a terminal illness, and I don't have a family," Karlstrand said in 2015. "I've received world-class medical treatment at the Department of Veterans Affairs Hospital in Minneapolis. I thought the least I could do was to sell my house and give the money away and then I heard about the Habitat program to rehab the house and sell it to a veteran.

"I've had a good life. Never sick until [2013]. I lived in a great house in a great neighborhood. It cost me $37,900."

Karlstrand, who is one of several Twin Citians who donates houses to Habitat annually, said his colon cancer spread to his lungs in 2015.

Habitat reveals more details on mortgage pool

Sunrise Banks is the first institution to commit to a planned loan fund of at least $75 million by Twin Cities Habitat for Humanity that would help up to 500 working-class families into refurbished and new houses over the next several years.

Habitat CEO Sue Haigh told a meeting of prospective business and other supporters last week that the fund would be aimed at helping to close the gap between what working-class buyers can afford and the real cost of delivering a house, the "gap" that often is closed by Habitat or a participating government.

"We have to bring costs down on a house or bring up the ability to access financing," Haigh said. "Our customers are people at 80 percent or lower of the Twin Cities-area median household income, which is about $71,000 for a family of five."

The Minnesota Housing Finance Agency, which provides Habitat with about $2.5 million in funding annually, is expected to soon make a commitment.

Last year, Twin Cities Habitat helped 44 families achieve homeownership. And Habitat International recently informed local chapters that the nonprofit agency has now become the nation's single-largest homebuilder, thanks to supporting businesses, funders and volunteers who help with construction.

If nothing else, that says something about the inability of working-class people to buy increasingly costly houses.

Haigh last week gave a briefing to business executives, including CEO Brad Hewitt of Thrivent Financial, which over the years has become Habitat International's single largest supporter; CEO David Mortenson of Mortenson Construction; CEO Hoyt Hsiao of Shaw-Lundquist Associates, another contractor; Barry Mason, managing director of IBM in Minnesota and chair of the Habitat board; Dave Reiling of Sunrise and Mary Tingerthal, commissioner of Minnesota Housing Finance.

Typically, Habitat makes interest-free loans and subsidizes prices to assist families who prove they will be good owners through financial counseling and work on their houses. They typically are not required to pay more than 30 percent of monthly income in payment. Most don't qualify for conventional loans.

Neal St. Anthony has been a Star Tribune business columnist and reporter since 1984. He can be contacted at nstanthony@startribune.com.