BANGOR, Maine — In some ways, it was sad for homeowners Keith and Beth Bisson to close all the windows and doors in their Fairmount Park home on a beautiful June day, shutting out the 70-degree sun and a pleasant breeze.

But if it helped to pinpoint energy inefficiencies in their home and identify easy and cost-effective measures they could take to improve efficiency, it was well worth it.

The Bissons hired a local firm to conduct an energy audit of their home on Royal Road, which they bought about 2½ years ago. The couple, who have a 19-month-old son, are among many who hope to take advantage of state and federal incentives available through Efficiency Maine, a program of the Maine Public Utilities Commission.

“We had been thinking about it for a couple of years, and we were replacing some old wiring in the attic recently and decided the timing was right,” Keith Bisson said Friday outside his home, a 1912 two-story “Bangor box.”

Andy Meyer, program manager for Efficiency Maine, said the summer months are the best time to conduct a home energy audit because contractors are not as busy.

“It’s not just about money savings,” he said. “Having a more efficient home is safer; it’s more comfortable.”

An auditor — in the Bissons’ case it was Penobscot Home Performance of Belfast and Bangor — uses diagnostic equipment such as infrared cameras, blower doors and combustion analyzers to assess the condition of heating systems, insulation and air infiltration.

Paul Shepherd, who conducted the Bissons’ energy audit on Friday, said the process takes about four hours, after which the auditor generates a report that details a homeowner’s options.

“We try to prioritize by energy savings and cost of retrofitting versus the return,” he said. “The biggest thing we see is too little insulation.”

The energy audit process was fascinating for the Bissons. By closing all the windows and doors and sucking the inside air out with a large fan, they were able to clearly see the drafts created by the door to their basement, the light fixtures and other areas.

Keith Bisson said the idea of an energy audit made sense financially but also appealed to an environmental ethic he and his wife share.

Meyer said a good rule of thumb for whether homeowners should conduct an audit is if they spend more than $1 per square foot per year in heating costs. The Bissons, whose home is 1,600 square feet, said they spent about $1,800 last year on oil.

An energy audit typically costs about $400 to $500, but many energy improvements are easier and cheaper than people think, according to Matthew Damon with Penobscot Home Performance.

“We target the low-hanging fruit,” he said.

Even the biggest retrofits such as boiler replacements are more financially feasible at the moment, thanks to cash incentives from last year’s federal stimulus package. Efficiency Maine is offering an extra $1,000 cash back this summer for homeowners who retrofit their homes. Meyer also stressed that the incentives are available to anyone regardless of income level.

The Bissons are not sure what their energy audit will reveal, but either way, they were glad to do it.

“I think it provides us with better information and options if we decide to make improvements in the future,” Keith Bisson said.

Information on weatherization tips, cash incentives and credits is available at