Shaping an entire story around one potent metaphysical metaphor, "Life as a House" overcomes many contrived and manipulative plot elements to prevail as a genuinely moving fable about a man building his dream house as he's dying of cancer.

The whimsically earnest Kevin Kline stars as George Monroe, a ramshackle guy with a ramshackle house that he's been talking about tearing down for 20 years. His wife left him when their now-teenage son was a toddler because George's lack of dedication extended to their marriage as well. The neighbors on his posh sea cliff cul-de-sac also turn up their noses at George and his eyesore of a peeled-paint hovel -- but since he enjoys tweaking those noses, that's OK by him.

Ironically, George is an architect -- albeit an architect so stuck in his ways that he's fired for refusing to get with the times and design on a computer. Long ago he blue-printed his dream home for the lot where his crumbling cottage stands -- but until he learns he's not long for this world, he's never had the tenacity to follow through.

Writer Mark Andrus ("As Good As It Gets") and director Irwin Winkler ("The Net," "At First Sight") construct the emotional framework of this film on a sometimes shaky foundation -- the predictably prickly relationship between George and his troubled, hostile son Sam (Hayden Christensen). Sam is forced to spend his summer helping with his dad's hair-brained construction project, unaware that their time together will be brief.

An angry, self-loathing punk full of facial piercings, toying with drugs and turned on by self-asphyxiation, Sam inevitably transforms into a comparably clean-cut optimist who dates the girl next door. Such a transition would be downright laughable if the movie's performances weren't so remarkably natural. Christensen (who plays Anakin Skywalker in the next "Star Wars" installment) completely submerges himself in his character's all-encompassing hostility, then looks within the kid's embittered soul to find an ember of devotion to his dad.

Kline is convincingly stronger of heart as George's body becomes weaker. As he tries to break through to his petulant progeny, you can feel grief and regret eating away below the frustrated causticity he throws up as a defense. The pair begins to connect in the cathartic act of taking sledgehammers to the walls of the old house. Living in the too-close quarters of George's converted garage gets them on each other's nerves but keeps them communicating as the new house begins to take shape.

Some ancillary characters are refreshingly complex as well. Sam's mom (Kristin Scott Thomas), whose well-to-do husband's indifference drives her to spend more and more time on the construction site, begins to see the same George she once loved reemerging as he works on the house they used to talk about building together. The aforementioned girl next door -- played by the suddenly grown up and alluring Jena Malone ("Contact," "Stepmom") -- uses Sam as a test subject for her budding sexuality, telling him he can shower at her house (there's no bath in George's garage), then jumping right in with him.

But other characters are little more than narrative devices used to develop a coincidence-filled subplot Winkler seems to feel is necessary for additional tension. Malone's mom (Mary Steenburgen) sleeps with her daughter's boyfriend, a high school stud who once tried recruit Sam as a gay prostitute (huh?!?). These facts later lead to an absurdly convenient solution to a dispute with a snooty neighbor who tries to stop construction on George's new house out of spite. "Life as a House" runs 128 minutes and while it doesn't feel long, without all this rigmarole it could have easily clocked in under two hours.

There are several other nagging problems with the film, like the fact that a dozen people work on George's house in the background, but no mention is made of who they are or why they're helping. It's also annoying that the movie equates Sam's straightening up with losing his identity as a punk. This is the second movie in a month (see "My First Mister") to imply that contentment and facial piercings are mutually exclusive.

But while "Life as a House" is nothing if not conventional, it never stoops to being maudlin or weepy like Hollywood terminal illness movies are wont to be ("Beaches," "Steel Magnolias," etc.). Winkler goes easy on the heartstrings and it pays off with bona fide poignancy that's sustained right up to the movie's closing credits.