SAN ANTONIO—Judith Markelz has relied on volunteers for years to help the war wounded and their families. They’ve brought meals, DVDs, event tickets and an endless supply of cookies to help comfort those whose lives are suddenly upended by a bomb or a bullet.

So when a new volunteer, Les Huffman, arrived at the chaotic 1,000-square-foot room used for the Warrior and Family Support Center in January 2007 and asked what Markelz needed, the program manager said a new video game system.

But Huffman, the president of a small commercial development firm, wanted to do more. And when Markelz conceded she could use a little more room, that’s what she got: a $5 million building designed like a Texas Hill Country home with a therapeutic garden, classroom, video game room and kitchen—all paid for by private donations. It’s the first center of its kind built on an Army post.

“I asked for an Xbox 360 and I got a 12,500 square-foot building,” she laughs. “Nice trade-off.”

Markelz gets the keys to the new place, built at Fort Sam Houston, on Monday.

The original support center opened five years ago and was expected to just offer a couple of activities a month and provide a small place for the wounded to hang out so they wouldn’t stay in their cramped barracks all the time.

But as the fighting in Iraq and Afghanistan dragged on, the number of severely wounded service members grew. Brooke Army Medical Center at Fort Sam has the Army’s only burn unit and a large amputee rehabilitation program, meaning many of the wounded are there for the long haul.

Their family members—usually wives or mothers—often drop everything when they get the call that their spouse or child is wounded and arrive in San Antonio overwhelmed. They forget diapers for their infants, don’t have more than a couple changes of clothes and don’t have any way of getting around the city.

But even after the immediate panic, the families have other needs. Sometimes, spouses need education or job skills, and they often need the diversion of crafts, meals and outings, Markelz said.

The new building gives them a lot more space and the ability to do things the cramped room didn’t.

A large kitchen will allow families to cook. A barbecue pavilion sits near a garden built for relaxation and therapy. A classroom will offer graduation equivalency diploma classes and other skills. A high-end game room designed by a couple of the wounded servicemen will allow for video game tournaments and movie nights.

Cash donations to the Returning Heroes Home, the nonprofit Huffman Developments set up to oversee the project, were supplemented by subcontractors eager to give their time and by suppliers willing to give materials for free or at steep discounts.

“I can guarantee, Yes, Virginia, there is a Santa Claus,” Markelz said, borrowing a line from a famous 1897 New York Sun editorial. “That much I have learned.”