John Haines tries out the climbing wall in the rec room of his family's home. His dad, Dr. Jim Haines, says the wall is part architectural statement and part diversion for his three sons.

And then there's the climbing wall, which stretches 20 feet to the ceiling and comes fitted with hand and foot holds as well as safety lines.

"We wanted to maximize the space and the indoor recreational possibilities for the kids, given what the weather is like up here sometimes," MacDonald explains.

Rich Johnston, owner of Vertical World (www.verticalworld.com), thought to be the first indoor rock-climbing gym in the U.S., installed the wall. Vertical World designs and builds these kinds of walls for parks, the military, companies and especially for schools now that more emphasis is being placed on noncompetitive sports.

He has also put them up in five or six homes around the Seattle area. Mostly, they've gone into rec rooms, but the walls have been placed in bedrooms and living rooms, too. The price: somewhere between $6,000 and $12,000.

"Usually, someone comes to us for a home wall because of their kids," Johnston says. "It's a way to use a wall."

MacDonald says neither of his two children, who are 12 and 13, climb yet, but he hopes they'll find the wall amusing and challenging. For him and his wife, also a former Microsoft worker, it represents another way to blow off steam. "And," he adds, "it's another healthy alternative to videos."

The brown wall is about 14 feet wide by 20 feet tall and consists of a series of square panels with faux-rock surfaces. At one point near the top, the wall creases and leans out over the room, creating an even greater challenge. Vertical World has a "route setter" who places the holds. MacDonald hopes he and his son get proficient and avid enough that they can alter the routes on their own to challenge their acumen and foster creativity.

Dr. Jim Haines has had a wall for a while as a way to give his three sons an outlet and practice for real rock-climbing. His is in an exercise and rec room containing everything from a pool table to weights to a treadmill. While the MacDonald wall is 20 feet high and relatively narrow, the Haines wall is 16 feet high and 20 feet wide.

"It's part architecture statement, part something to do for the kids on a rainy day," Haines says, though he confesses it's probably more decoration now that his youngest is off to college.