"The idea is how to use energy properly in your house and how to improve," he told a small gathering at a Sunbay Energy speaker series presentation.
He said the purpose of having an audit done is to save money on energy, increase the comfort level of your home, be environmentally friendly and increase resale value.
"You have to learn about how homes operate as a whole," he said. "And we must be conscious of how one thing affects the other."
It was proposed that energy audits become mandatory upon purchase/sale of a home, but the audit process needs to be perfected first, he says.
"The proposed law to require energy audits has been pushed back, but it's not dead," Underwood said.
He'd like to see electricity become part of the energy audit as well as the typical air leaks, etc.
There's a lot of phantom electricity that is used just because you have TVs, computers and other items plugged in, he says.
"They all use energy as long as they're plugged in," Underwood said.
But before you hire just anyone to perform an audit, he says, you should shop around.
You have to verify an auditor is certified or you won't qualify for the available government grants, and you should ask how much experience the auditor has and who actually writes up the report, Underwood says.
Although there are names listed on the Natural Resources Canada website, he says you must still verify their credentials to ensure you get what you're looking for, and suggests you visit https://oee.nrcan.gc.cafor helpful information.
Courses are currently offered at Humber College, with Durham College expected to offer a home audit course in the near future, he says.
And what happens after your audit and the work is complete? You have to take a look at your lifestyle and try ways of reducing your power consumption, he says.
"Do you really need those four TVs plugged in?" he said. "Do you really need your computers on and plugged in?"
Underwood suggests taking advantage of the free literature provided by the government.
"TheEnerGuide, Keeping the Heat In, is an excellent book for the average homeowner," he said.