MEDFIELD -- All over America, little boys play outside in their backyards, and when their mothers call in them for lunch, they go back in.
It's as mundane a domestic scene as you can get. And usually, it's not a cause for celebration.
But it was recently at Heidi and Tripp Johnson's house, where the little boy in question is their 6-year-old son, William. As a baby, he was diagnosed with spinal muscular atrophy, a genetic motor-neuron disease that has so severely weakened his muscles that he uses a wheelchair. He needs to be propped up when he sits, and ''he's never walked, ever," his mother says.
Before his family's old New England non-handicapped-accessible farmhouse was rebuilt in a major undertaking spearheaded by ABC's home renovation show ''Extreme Makeover: Home Edition," it took a staggering amount of supervision, energy, and effort for William to get through his daily activities, let alone play in his own backyard, where he had to contend with steps and cobblestones, and circumnavigate a flower bed and 6-foot rock ledge.
Last month in a 106-hour construction blitz involving a slew of builders and hundreds of volunteers, the Johnsons got a whole new house designed with William's independence in mind. The show airs Sunday at 8 p.m. on WCVB-TV, Channel 5.
It has an open floor plan so William can zip around the house in his Segway-like mobile ''stander" and chase his 10-year-old sister, Abby, as he did one day last week until his mother intervened: ''Don't torture her!"
It has wide doorways, a roll-in shower, an elevator to the second floor, and an elegant ramp leading into the house that's integrated into the porch and landscaping so it ''doesn't scream out, 'I have a disabled child here,' " Heidi says. It has a bedroom for William next to his parents' so they can monitor him during the night and move him when he's uncomfortable, since he lacks the strength to turn himself.
It's more than twice the size of the old house, and Heidi says ''it's luxury all the way," loaded with the kinds of high-end appliances, electronic gizmos, themed rooms, and other over-the-top details that fans of reality-TV shows have come to expect, such as a Red Sox-themed family room and a scaled-down version of Fenway Park in their backyard, complete with baseball diamond, Green Monster, and Pesky Pole.
But ''these are luxuries that don't matter to us," Heidi says. What matters is what happened the first time William played in the new backyard with a friend unsupervised and his mother called him in for lunch.
''I said, 'Boys, it's lunch,' and he came in for lunch," Heidi says, pausing to let the effect register. ''I was bawling my eyes out, and he said, 'Why are you crying?' I said, 'Because you came in for lunch.' "
There is ''magic" in the new house, she says, and it's an alchemy that goes far beyond the TV-induced miracle by which a crew was able to ''move out 40,000 pounds of our prior life," pack it in crates, raze the house, grade the yard with 5,000 tons of backfill, and build, decorate, and landscape a whole new house, all in a week.
The real miracle, say William's parents, is that their son can have a semblance of a normal and independent life, something probably not possible for many other young children with severe disabilities, given how unlikely it is that carpenter/TV host Ty Pennington is going to show up at their front doors with a bullhorn anytime soon.
But what the story of the makeover of the Johnsons' house only hints at is that even now, at a time when biomedical technology is so advanced, it's still difficult for children with significant physical disabilities to lead lives that are anywhere close to independent.
''We're still dealing with an issue that has not been given enough attention," says Valerie Fletcher, executive director of Adaptive Environments, a Boston nonprofit that advocates for accessible design. ''Autonomy for even little kids with significant disabilities is precious," she says. ''Independence is such an important marker for development."
William may be physically handicapped, but he goes to kindergarten, has lots of friends, is ''smiling, happy, and outgoing," says his father, Tripp, and cognitively, ''he's a little brainiac," says Heidi. ''He's at the top of his game."
But before their house was rebuilt, his home life was restrictive. He could only access three rooms of his house because the doorways were narrow. He needed to be carried upstairs to his bedroom. He needed -- still needs -- assistance in the shower and bathroom.
''Who wants to have a mom there all the time?" says Dr. Virginia Kharasch, a pediatric pulmonologist at Franciscan Hospital for Children who has treated William, and was a medical consultant to the TV show. ''Every child wants to be independent. The technology is there, but we have not invested enough of our creativity to help children with special needs. Wouldn't it be nice if you could wheel your wheelchair into the shower area, and wave to a sensor that would change the temperature of the water to your desired degree? There is no reason, in this age, that you couldn't have a totally computerized system that would actually address each handicapped child's needs for such basic needs as toileting."
Heidi agrees, but this is all beyond her dream. ''I feel like I've won the lottery," says Heidi, whose family was chosen for the show after Heidi's sister, Erica Stahler, wrote a letter to the producers describing the family's situation. Not only did William have a life-threatening illness, she wrote, but his diagnosis came only months after Heidi was diagnosed with ''a second more serious site of melanoma," and days after Heidi's mother underwent brain cancer surgery.
''Despite providing William with full-time care, managing her own ongoing health issues regarding melanoma, and having stepped in to assist her father with his home inspection business following her mother's illness and subsequent death, Heidi still finds time to devote to promoting awareness and raising funds to find a cure for SMA," Stahler wrote. William, she added, ''inspires every member of our family. . . . He's a normal kid, but his legs just don't work."
Heidi says, ''I feel awful for the average family" who has not been as lucky as she has.
Still, ''independence is very different than accessibility," she points out. ''We have nothing to complain about, but the reality is that being independent means you can open a door by yourself, and William can't do that in his home. We have a wonderful elevator in our house, but he has a friend with SMA who is just that much weaker than he is, and she can't operate it. William can access the second floor of his house now, but he can't close the elevator door by himself. He can't transfer himself from a wheelchair to a toilet."
The reality, says Heidi, is that living with a serious disability requires a certain amount of acceptance, ''and running with it in the best, positive way we can, rather than hiding it or being ashamed of it. My husband and I are not willing to let him feel all that much different; God made him different already and we can't limit that anymore. When you have a child with a disability, you have to let them feel like they participate in life fully, like anyone else."
The new house helps them a lot, she says, by ''eliminating some of the stresses we had before the safety issues, going up and down the stairs." If there were one design modification she would like to see in the homes of all children with disabilities, it would be that they could feel ''the power of entering their own homes. They'd have doors that let them press a button and come in. If people could just enter their own homes independently, and feel that welcome into their own home, that would be huge.
''This is not to say there aren't days when I wish it wouldn't just all go away and we could have an average life, especially when you are dog tired from being up all night with a sick child," she says. ''But there are huge, huge blessings to having a child like William, and that's what we focus on."
One of which is seeing how much ''winning the lottery" has done for William.
''It is really good. It's really much better for my Mom and me," William says. ''She doesn't have to lift me anymore, except to the bed. I can get around the kitchen. I can get around the Red Sox room. And I can get around the baseball field!"