Single family homes that disclose their energy costs on a real estate listing spend less time on the market and sell for a higher price than homes that do not include this information, according to an analysis by the Chicago, Illinois efficiency program company Elevate Energy.

According to the study, attached homes such as condominiums and townhouses in Chicago that made an energy disclosure sold for 97.2 percent of the initial listing price on average, while homes that did not make the disclosure sold for an average of 95.9 percent of the initial listing price. On a property listed for $352,000, the average sales price in Chicago for the period of the study, this would net an additional $4,576 at sale if energy costs were disclosed.

Elevate Energy also determined that homes with disclosed energy costs spent less time on the market. Attached homes that did not make an energy disclosure spent an average of 93 days on the market, while those that noted their energy costs spent an average of 69 days between listing and sale. Detached homes spent 104 days on average with an energy disclosure and 111 days without one.

In July of 2013, Chicago became the first municipality in the United States to permit the disclosure of residential gas and electric costs on a multiple listing service when a single family home or a home of two to four units was listed for sale. This effort was a joint partnership of the Chicago mayor's office, Elevate Energy, the multiple listing service for the Chicago area, and the Chicago area real estate service Midwest Real Estate Data.

The partners also introduced an "Energy eCompliance" tool to provide online access to a property's energy cost disclosure report. This tool was designed to help listing agents provide buyers with information on a property and comply with the time requirements of the energy cost disclosure ordinance.

Elevate Energy says that in addition to encouraging higher sales prices and faster sales, energy cost disclosures will help inform buyers about the monthly expenses at a property.

The analysis reviewed the first 18 months of data after energy cost disclosures were allowed. It includes single family homes in the Chicago area that were listed between July 1, 2013, and Dec. 31, 2014.