Homeowners who want a home that keeps their families comfortable and at the optimal efficiency level likely have a big investment ahead of them.

According to John Krigger, co-author along with Chris Dorsi of "The Homeowner's Handbook to Energy Efficiency," the average homeowner must spend between $10 and $30 per square foot to bring their homes up to snuff. For a 1,500-square-foot house, that amounts to a $15,000 to $45,000 expenditure.

The good news, Krigger says, is that investment will pay for itself within a decade. Plus, he points out, improving your home's efficiency improves the resale value. According to the National Association of Realtors, every dollar spent on efficiency will bring as much as a $25 return at resale.

Krigger said he and Dorsi started working on the guide 10 years ago. It wasn't until the world energy crunch started hitting close to home for many people earlier this year that the Helena book publishers and authorities on home energy thought America was ready for the book.

"We didn't think the interest was high enough before this year to release it," Krigger said. "We thought, 'This looks like the situation we've been waiting for.' "

Dorsi and Krigger are both longtime advocates of energy-efficiency.

As a home-builder and real estate developer, Dorsi has worked on creating the next generation of energy-efficient homes. Krigger is an expert on super-efficiency and a zero-energy approach to construction.

Over the years, the two have written and published more than a dozen books on the issue, mostly aimed at people working in the construction industry.

Their latest book guides readers through the entire process of improving energy efficiency.

The book instructs readers on how to develop a plan for their homes, and details energy-efficient lighting and appliances, water heating, heating and cooling, landscaping and finding and sealing leaks.

Krigger said there are a number of things that don't require a lot of money or effort that can have big returns.

One of the biggest is to install programmable thermostats, allowing the temperature of the house to be lowered at times of the day when no one is home. That alone can save 10-20 percent on energy bills, Krigger said.

Other easy fixes:

• Replacing incandescent bulbs with low-energy compact fluorescent bulbs;

• installing low-flow shower heads

• reducing the temperature of the hot-water heater to 120 degrees and wrapping the heater with installation.

Doing those three things can mean up to a 15 percent savings.

Krigger said that over the years in the home industry, saving money and finishing projects has trumped building homes with efficiency in mind. That mindset has led to a nation full of inefficient, drafty homes.

He said the biggest thing that can be done to seal leaks in a home are improving the windows.

"Windows are something that need to be done right," he said. "Cutting corners is how we got into this energy crisis. Everything uses 50 percent more energy than it needs to. Now we're getting our comeuppance."

Features editor Joe Menden: joe.menden@helenair.com, 447-4087.