How much energy do the homes save?

Phius-certified homes are designed to deliver healthy indoor air, consistent comfort and significantly lower utility bills to reduce monthly housing costs, according to the organization’s website.

How much lower bills?

With 1,680 square feet, 3 bedrooms and 2.5 baths, the all-electric homes in Dover are designed to use about 7,500 kilowatt hours of electricity a year, about 625 kilowatt hours per month.

That’s about 30% less than what the average home uses – 10,791 kilowatt hours per year or 899.25 kilowatt hours per month, according to the U.S. Energy Information Administration.

Norm Horn, New Ecology construction project manager, outlined the key components in the energy-efficient construction including:

• continuous insulation around the outside of the home, higher levels of insulation in the walls, under the floors and in the attic and “significant attention to how that insulation was installed so it works”

• a thermal airtight building enclosure that requires very little energy to heat and cool

• highly efficient heat pump systems for heating, cooling, the water heater and clothes dryer

• dehumidifier system to control moisture

• continuous mechanical ventilation with heat recovery that provides fresh, filtered air

New Ecology Chief Executive Officer Kim Stevenson said the construction techniques used in these homes help the owners in several ways.

Utility bills can spike during winter’s cold and summer’s heat if homes don’t have good insulation, good windows and doors or proper sealing around them.

“That forces families to make impossible tradeoffs between paying utility bills, rent or mortgage, food and health care,” Stevenson said.

The Phius homes can decrease monthly utility bills while also improving residents’ health with moisture control to prevent mold along with top-quality air circulation for cleaner, healthier air.

More on utility costs: ‘An energy affordability crisis’: Action urged on easing utilities rate hikes

These four homes will be examples for others to follow in trying to make homes more affordable, more energy efficient and healthier, as the nonprofits leading the effort expand the training to more builders.

Tony DePrima, Energize Delaware treasurer and former executive director, said the homes will be part of a research project, comparing data including utility bills to more typical homes to see the cost savings over time.

Energize Delaware is “trying to figure out how do we make this work for the people who need it most,” DePrima said.

Reporter Ben Mace covers real estate and development news. Reach him at rmace@gannett.com.