Amy Smart engaged to HGTV's Carter Oosterhouse

An insider says the proposal happened four days ago and took place in L.A. "It was a very big surprise but she is thrilled and very excited," a snitch source says. "They are perfect for each other."

Smart, 31, and Oosterhouse, 34, met in November 2010 at a green-charity event. "He's an eco-carpenter; Amy drives a hybrid and is the greenest girl I know," a source gushes. "They are perfect for each other." Oosterhouse is well-known for his work as carpenter on TLC's "Trading Spaces" and his hosting gigs on HGTV's "Carter Can" and "Red Hot & Green."

A source says, "Here are two wholesome, kind, sweet Midwestern types. Neither has sold out and gone Hollywood." Smart ended her 15-year relationship with Branden Williams last year.