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Do-No-Harm Dwelling

What makes up a net-zero house?

Seth Lawrence-Slavas ’17, ’19MA, CEO of Wright Builders, builds in western Massachusetts with a long-term view, solving not only immediate housing shortages but also making sure we don’t end up with the same problems in 30 years. That means looking at existing buildings and figuring out how to make them cost-effective and more sustainable. Each case is different, and Lawrence-Slavas relies on software and low-carbon materials to help make decisions that have the lowest impact on the climate.

Long-term thinking is at the core of Lawrence-Slavas’s building philosophy, and that starts with the impact his projects will have on the planet. “We’re trying to do no harm here,” he says. “We’re not just building code-minimum buildings that are going to last 30 years and then need to be replaced.”

Built into this long-term thinking is the idea that buildings should be efficient and fitted with the latest clean-energy technology to keep the cost of living low. “What people talk about in affordable housing is also that once you get people into that housing, there are still continual costs. So, eliminating energy costs, creating efficiency, that type of thing, it actually makes those building projects more feasible.”

So, how can you build a more sustainable house and save money? Here are some great places to start.

House with solar panels on roof and pine trees in the foreground


When it comes to building an environmentally friendly and sustainable home, design is at the core. Unused rooms and unnecessarily high ceilings can nix a house’s hope for sustainability. In a net-zero house, each component’s elements are calculated for their carbon footprint and other measurable byproducts in an effort to offset or make up for them with other elements in the house and its systems.

Solar panels on the roof of a house on a forested hillside under a partly cloudy sky


The biggest help in offsetting carbon emissions is the use of the sun. A net-zero house will face “solar south” in order to allow solar panels to absorb the most sunlight possible throughout the day, as well as to collect and store the energy of those rays for later use.

Seth Lawrence-Slavas installing windows in a shaded room


The Environmental Protection Agency says that although windows constitute only 10% of the surface area of a typical house, about 30% of heating energy is lost through standard double-pane windows. But adding extra glazing can cut that heat loss in half. That’s why net-zero builders almost exclusively use triple- and even quad-pane windows.

Close up on the outside of a house with green ZIP System insulation exposed


Another way green builders are keeping houses warm is a new method of insulation. Starting with a double-walled application, a ZIP System® Insulated R-sheath is inserted between the outer stud wall and the siding. Its built-in exterior insulation helps to reduce heat transfer. The ZIP sheath is also water resistant, and the ZIP System provides a tight barrier that reduces the amount of air leakage—keeping the indoor environment consistent while using less energy.

White room with wires and metal pipes coming out of the ceiling


With an (almost) hermetically sealed house, you need to mechanically pump in and circulate fresh, filtered air. Most net-zero houses do this in two steps. First, a heat pump (which condenses warm or cool air from outdoors) acts like an air conditioner, heater, and dehumidifier all in one unit, pushing air at a set temperature into the house. Then, an energy recovery ventilator filters and recirculates indoor air—passively utilizing the warmth generated by appliances in the kitchen, steam from a hot shower, and even people’s bodies. This can save up to 70% in heating bills compared to a traditionally constructed house.

Exterior of gray and green house and yard with stone patio


You don’t need to build a new house—and in some cases, you don’t even need to own a house—to green your living situation. If you live in Massachusetts, you can take advantage of the state-run MassSave energy assessment and audit program, which includes a free annual inspection and consultation session for homeowners and renters alike and offers tens of thousands of dollars in rebates and no-interest loans for work the program auditor recommends.