Electrification is a natural evolution in how we’ve historically fueled our homes, as many homes operating on gas today were originally fueled by coal or heating oil. In the mid-1900s, most homes converted to gas as the primary fuel source, as it was cheap and relatively clean compared to coal or oil. As natural gas prices continue to rise and the impacts of carbon emissions are felt by communities, pressure has increased to find a way to decarbonize our homes. We are witnessing the beginning of the era of the net-zero home.
Sustainable builders have embraced airtight building envelopes, electrification and solar photovoltaics (PV), also known as solar panels, in builds for sale on the MLS, raising the stakes for homebuilders who are still building homes with gas lines. All electric and net-zero homes have given sustainable builders a competitive advantage, delivering homes that are more comfortable, durable, healthier and quieter; they also require less maintenance and cost less to operate. Who wouldn’t want that?
As REALTORS®, the best way to market and sell high-performing homes is to understand the benefits these homes deliver to homebuilders, developers, the marketplace, homebuyers and the environment.
The net-zero home differs from region to region, depending on climate and local construction methods and standards. In the Chicagoland area, we’re faced with harsh winters as well as hot, humid summers — a true challenge for builders. Net-zero homes are typically grid-tied homes equipped with solar PV on their rooftops. They exclusively use electricity as fuel and don’t have gas lines.
In Chicago, net-zero homes tend to overproduce power March through October, when the days are long and sunny and the weather is milder. Excess power is sent to the grid to be used by neighboring homes. Through this, the home treats the grid as long-term storage for power that will be needed in the colder months, when heating demand increases energy requirements and shorter days reduce energy production.
By using net metering, it’s possible to size a solar PV array (a collection of multiple solar panels), to produce as much power as a home is likely to consume over the course of a year. For example, a home fitted with a solar array that generates 9-megawatt hours per year is fitted to a building estimated to consume the same amount. This way, electricity power costs are reduced to the base delivery charge and fees, and any carbon-based power the home consumes is offset by the renewable power generated on the rooftop.
Of course, building a net zero home takes planning and the right team. Typically, builders will contract with an experienced energy consultant to help them look for cost effective solutions to reduce energy needs and improve quality, comfort and health.
Here are some of the basics a development team considers prior to construction:
Insulation and Building Envelope
High-performing homes are air sealed, with better building wraps and better insulation strategies. You can usually feel and hear the difference compared to homes without these high-quality materials, as this translates into a home free of drafts and hot or cold spots. Triple pane windows offer opportunities for larger windows with more light and more connection to the outside world. Imagine enjoying a polar vortex view while you’re cozy and warm at your picture window! The combination of super-insulated envelopes and enhanced windows also reduces sound transmission, which helps quiet the home’s interior, blocking out noisy neighbors and rush hour traffic. Who doesn’t want a more comfortable and quiet home? In my experience, buyers are typically in awe of the library-quiet interiors.
Healthier Indoor Air
Indoor air quality in an airtight home is intentional. Standard homes rely on the inherent “leakiness” that comes with typical construction methods, but being airtight reduces the ability for outdoor air to find a way in, minimizing the infiltration of allergens, pests and other pollutants into the home.
In an airtight home, healthy indoor air quality is managed by carefully commissioned systems that make sure the occupants have clean, fresh air supplied with the use of Energy Return Ventilators (ERV’s/HRV’s). These simple systems constantly exchange inside air with filtered, fresh air, while conserving the heat in the system by using a heat exchanger to precondition incoming fresh air with heat from the exhausted air. A home fit with an ERV has fresh air, much like an open window, without the energy penalty, year-round. An ordinary home can’t make that claim, as it relies on air leaks or open windows.
Moving the home’s system away from natural gas to electrically-fueled appliances is simpler than it seems. Most high-performing homes have migrated away from natural gas and combustion entirely.
Here’s how many homes have made the shift:
HEATING AND COOLING: Electrically powered heat pumps are replacing gas furnaces and central air conditioners. For heating and cooling, cold climate heat pumps do an incredible job of making homes more comfortable year-round. These systems don’t over-cycle or use on-off cycling like most HVAC systems. They keep the interior temperature and humidity nearly constant by running at the exact speed needed to maintain the temperature set on the thermostat. Due to the building envelopes of net-zero homes, the heat pump uses power slowly and is nearly silent in operation.
DOMESTIC HOT WATER: Hybrid hot water heaters use less electricity than tankless hot water heaters and cost less to operate than high-efficiency gas water heaters. Hybrid systems use a heat pump to move heat into the home and water tank. Moving heat is about three times more efficient than making heat, and these units typically cost less than $115 per year to operate, versus the $200+ dollars per year cost of efficient gas and tankless electric models.
COOKING: I know most of you will say, “My clients only want to cook on gas stovetops.” Well, I believe anyone loyal to gas cooktops hasn’t had a proper introduction to induction cooking. Most informed cooking enthusiasts and chefs will vouch for induction’s superiority to gas: it’s faster to boil and sear, with more power being transmitted more quickly to the pan. It’s more precise than many cooktops and can melt chocolate and butter without scorching. It’s also more efficient, as the cooktop stays cool to the touch, only heating the pan, and you won’t have to be concerned about the potential for combustion. Also, with homes getting more airtight by code, replacement air and exhaust systems need more scientific consideration for gas combustion to be safer indoors.
DRYING CLOTHES: Heat pump dryers remove moisture from clothes gently and pump the moisture into the plumbing system. They also use very little power and don’t vent valuable heat to the outside. These units are state of the art and make electric drying a lot greener.
RENEWABLE ENERGY: This is a hot trend right now! With carbon-based fuels at near record prices, making your own power is an attractive option. Before you tell your clients to install solar, consider the following:
- Take Pam Brookstein’s class on Solar for REALTORS®. You’ll learn all the tools you need to become an expert on the complex consumer world of renewable energy.
- Look at reducing the home’s overall electrical consumption before considering installing a solar system. Solar panels cost money, and fewer panels may be needed if you properly build the building’s envelope and commission the HVAC systems. After all, insulation is cheaper than solar. Remember, one watt saved is equal to one watt produced by solar in terms of decarbonization!
Energy Efficiency Documentation
Once everything has been put into place, look for documentation. Most energy-efficient homes will be “rated.” There are many standards builders can choose to follow; some popular ones are LEED for Homes, Pearl Certification, PHIUS and Energy Star. Most of these certifications will require verification of the home’s performance once constructed. It’s not unusual for consultants to do a blower door test to verify airtightness and inspect all ductwork and HVAC systems for proper sizing and installation. Once rated, most homes will have a HERS Score certificate, which rates the home on an objective scale and indicates the anticipated annual savings of that home.
So, keep your eyes peeled, and get excited to see more of these homes on the market in the future!
Check out sustainability-focused classes, like the Green Designation, High-Performing Homes: Stand Out From the Crowd, and more through REALTORS® Real Estate School, and access sustainability tips, tricks & resources from our Sustainability Work Group.