"The city of Austin, Texas, has begun requiring homeowners to conduct energy-efficiency audits before they can sell their house. [Such audits] can include a review of a home's air-conditioning and heating systems, insulation and air-tightness, and generally cost owners from $200 to $300... The Austin ordinance requires residents selling single-family homes more than 10 years old to obtain an audit and provide the information to potential buyers.. [T]he new law doesn't require buyers to follow through with improvements... [The Austin Board of Realtors agreed to support the audits after that provision - a requirement in similar Berkeley and San Francisco, California laws - was removed.] City leaders say the required audits would help keep Austin from having to build a 700-megawatt power plant by 2020 by alerting residents to energy- and money-saving options.."

Energy Audits Vex Austin's Home Sellers | By TOM BENNING | The Wall Street Journal | JUNE 8, 2009

As outlined by Austin Energy, the city's public electric utility company, the audit must be performed by an auditor who is a certified Residential Energy Services Network (RESNET) Rater or a Building Performance Institute (BPI) Building Analyst Professional. Other details are about the new law on Austin Energy's website.