The Robo Retrofit House

March/April 2011
A version of this article appears in the March/April 2011 issue of Home Energy Magazine.
Click here to read more articles about Auditing
March 05, 2011
Much is learned from a side-by-side study of a retrofit home and standard-built home.
A home built in the mixed-humid climate of Knoxville, Tennessee, with energy efficiency upgrades used 42% less energy than an identical standard built home in a side-by-side measured and modeled comparison. The two-story homes have three bedrooms, 21/2 baths, and 2,400 ft2 of living space. The house type, size, and dominant features were selected after a demographic housing study in the Tennessee Valley Authority (TVA) service territory determined that this was a typical house on the market from 2000 to 2008. The energy efficiency packages, all commercially available in the area, made a significant difference in energy use between the two houses. The Retrofit House has a HERS index of 68 (a HERS of 0 is a zero-energy house; a conventional new house would have a HERS rating of around 100). The identical Builder House next door has a HERS of 102.

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