Jessica Alba

Jessica Alba is the celebrity volunteer on "Extreme Makeover: Home Edition" Sunday on ABC.

Jessica Alba is no stranger to makeovers.

Now she knows more about them than ever, since the glamorous actress has expanded the definition to include the overhaul of a deserving family's residence. She's the celebrity volunteer joining Ty Pennington and his "Extreme Makeover: Home Edition" team of designers on the Sunday, April 4, episode of the ABC series.

"I'm a fan of the show," Alba says, "but I don't think (the producers) knew it. I think it's fantastic what they do for families, and I love the idea that people in communities all over our country support these families."

Benefiting from Alba, other volunteers and the "Extreme Makeover" regulars are Larry and Melissa Beach of Texas' Gulf Coast. Their home wrecked in 2008 by Hurricane Ike -- and their stored possessions ravaged by flooding -- they've lived since in a small trailer with their four sons and nine adopted youths. Many of the Beaches' adopted children are impaired mentally or emotionally.

"It's just incredible what this family has done, with the conditions they were living in," Alba says. "The fact that 15 people had to pack into this 30-foot trailer was unbelievable, and the mother and the father still had the wherewithal to donate their time and give back, even living that way."

Alba considers the Beaches symbolic of many families still struggling to recover from such crises as Ike and Hurricane Katrina. "When there's a natural disaster, it goes beyond the immediate destruction. We all see the before and after, and these people are still living with it years later. Tons of people are in homes that aren't really fit or healthy or safe for their children."

As braced as she thought she would be for the rebuilding, Alba ultimately got caught up in the emotion: "Just seeing the volunteers -- these thousands of people who have to put food on the table for their own families, and are struggling to make their own mortgage payments and keep their lives afloat -- take a week to help this other family, it was so moving to know there are people who have such a sense of community and social conscience."