Photos of former model Carter Oosterhouse plaster the walls of many a dorm room. But his pinup looks notwithstanding, Oosterhouse's real talent lies in knowing how to swing a hammer. A carpenter by trade, he got his start on TLC's redecorating show Trading Spaces. HGTV then nabbed him to host Red, Hot & Green and Carter Can, which emphasize environmentally friendly design.

He's a regular on Oprah and Rachael Ray, showing viewers how to gussy up their homes in the greenest of ways. His nonprofit, Carter's Kids, builds parks and playgrounds in low-income areas.

Q: How did you get into carpentry?

A: It started out as a summer job in the town I grew up in, Traverse City, Michigan. It was just something to do to make some money. My two older brothers taught me, and a neighbor took me as his apprentice. I would have never guessed that what started as a summer job would take me so far.

Q: What made you an environmentalist?

A: I blame my dad. He was always preaching. Whenever we'd have to wash a car or boat, we had to use biodegradable soap. In Michigan we have such big bodies of freshwater—they're among the richest commodities we have—so that's why my dad was so adamant. We didn't realize that it would, but stuff like that got stuck in our heads.

Q: What do you tell people who say that eco-remodeling is too expensive?

A: I tell them that, yes, they may pay a bit more up front, but they'll save a bundle down the road. That's true with lighting and solar panels and anything that saves energy. With climate change, it's about being aware of what we're putting in the atmosphere.

Q: How did you meet your wife, actress Amy Smart?

A: We literally met in a garden. Through a nonprofit, we'd been planting school gardens in L.A., and we were paired on one of those projects. Our wedding was supergreen. We composted as much as possible. We had 220 guests and just one bag of trash.