When Bruce Sullivan set out to build his dream retirement home in 2015, his goal was to get his utilities costs as low as possible. Today the 900-square-foot Bend, Oregon, home that he shares with his wife has more than accomplished that, he said. The one-bedroom, one-bathroom house is what Sullivan calls a "zero energy" home.

Bruce Sullivan's energy efficient home in Bend, Ore. Bruce Sullivan

"It actually generates more electricity, more energy overall, than it uses," Sullivan said. "And it charges our electric car." That's quite an accomplishment. Saving energy isn't just good for the planet, it's good for your wallet, as well. But energy guzzlers, such as the cooling and heating systems in your home, can cost hundreds to operate each month. For Sullivan those savings have been achieved through the home's unique construction. That includes 10-inch thick walls and a 16-inch thick insulated roof. The home also faces south, which helps to provide solar heat. In addition, the house has rooftop solar panels that generate more energy than the couple uses for 10 months out of the year. As a result, Sullivan's energy bill is just $10 per month to cover the administrative fees the utility company charges. The monthly water bill is also low, due to dual-flush toilets and low-flow shower heads. Sullivan is counting on the continued savings to help his bottom line. "Those are earnings that will come back to me over time, and it just gets better every year," Sullivan said. For owners of existing homes, the good news is, it is possible to reach zero energy through improvements, according to Sullivan, who serves as the technical director at the Zero Energy Project, a nonprofit organization aimed at helping homeowners reduce their carbon emissions and energy bills. Even smaller-scale tweaks — such as installing insulation or new energy technologies — can result in substantial savings, from hundreds to thousands of dollars per year. There are several ways to go about this. You can hire professionals, do it yourself or use new technology products on the market.

Seeking professional guidance

When it comes to fixing up an existing home, using a professional can really help assess what improvements are needed, according to Sullivan. To get the right help, make sure you're working with a certified professional. There are two main organizations that offer certification: the Building Performance Institute and the Residential Energy Services Network, or RESNET. RESNET also provides a home energy rating system, which scores homes based on their energy efficiency. Once raters do a professional analysis of your home, you can see which areas need improvement. This kind of assessment can help if you plan to use a lender to fund upgrades, Sullivan said.

For example, a homeowner could borrow $25,000 or $30,000 with a home improvement loan and use that money for energy conservation efforts, such as sealing heating leaks or installing solar panels. "If you can borrow the money to do it and your savings exceed your financing costs, then you just got free improvements," Sullivan said. Now, in particular, is a good time to consider solar energy systems, as the tax credits of those installations are set to go down after this year, Sullivan said. In 2019 you can deduct 30% of the cost of installation from your federal taxes. In 2020 that will go down to 26% and will get further reduced in subsequent years. "Use your professional to create a plan so that you will do the most cost-effective things in the right order," Sullivan said.

Doing it yourself

If you do not have much cash available, there is good news: There are improvements you can make without a professional and without paying a lot up front. The Community Energy Project, a Portland, Oregon-based nonprofit, helps local residents of all economic backgrounds make home upgrades that can help them save both energy and money. While the organization can match homeowners with the right contractors and lenders, it also provides educational services to help individuals make these improvements on their own. Among the more popular upgrades for do-it-yourselfers: putting in new insulation, according to Peter Kernan, program director at the Community Energy Project. Because heat flows like liquid, holes in insulation can result in huge losses, Kernan said. More from Impact Investing:

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This app helps you invest responsibly By thinking of a home as a six-sided box — including the attic, walls and underneath the floor — homeowners can plug those gaps and stem those losses, he said. "Adding insulation is the biggest thing that will make an impact on your home," Kernan said. Of course, before taking on those renovations, homeowners need to make sure there are no health or safety concerns, such as asbestos or old wiring. For four walls, insulation can run from $3,000 to $4,000, with the help of a certified contractor, Kernan said. But if you decide to do it yourself, the cost is substantially less, Kernan said, in the range of hundreds of dollars. Plus, if you are buying enough insulation, you can sometimes rent the blowing machine needed to install it for free, depending on the store, he said. By adding new insulation and putting in high-efficiency heating systems, individuals can help bring a home's total utility costs down from $2,000 per year, on average, to $1,000, according to Kernan.

New tech tools

Homeowners with a more hands-off approach may want to use technology to help assess where they are wasting the most energy. One company, named Sense, is providing a home energy monitor to help identify those energy drains. Once the company's technology is installed inside the electrical panel of your home, it measures how much energy is being used in real time. "If you can get visibility into where your energy is going, most homes have these couple of gremlins that really could save you if you know what they are," said Mike Phillips, co-founder and CEO of Sense. One single device could be a major energy drain. For instance, simply unplugging a treadmill could help immensely. Some other big culprits include older TVs, game consoles and other entertainment-related equipment. Once those power wasters are identified, homeowners can either disconnect the device or use a smart plug to regulate its use.

If you can get visibility into where your energy is going, most homes have these couple of gremlins that really could save you if you know what they are. Mike Phillips CEO, Sense