When Corbett Lunsford got out of the music business and took up building diagnostics and consulting, he learned that old hands in the industry weren’t always interested in sharing their trade secrets. They were, in fact, “a little bit cranky” when Lunsford came calling.So the Chicago-based Lunsford vowed that when he became more established, he’d share what he knew with anyone who was interested — for free.The result is a series called The Building Performance Podcast. To date, Lunsford has produced 58 podcasts ranging from 15 minutes to 45 minutes in length. You can listen to them online or download them as MP3 files.The podcasts are a sideline for Lunsford, the managing director and trainer of the Green Dream Group, a company which he started with his wife, Grace Lunsford, in 2008. About 60% of his time goes to Green Dream, which performs building diagnostics, and about 40% to the Building Performance Workshop, which trains others.Lunsford produces all of the podcasts himself, recording them “guerrilla style” with his iPhone. He says there are about 2,000 downloads per episode.The podcasts also have become a learning tool as Lunsford tracks down and interview experts on topics he’d like to learn more about it. In that sense, he says, the podcasts are a little selfish.Lunsford, a HERS and Passive House Institute U.S. rater, is also author of a book, Home Performance Diagnostics: The Guide to Advanced Testing.