What?

The Built Green® Net Zero Energy Label indicates that a project has demonstrated via an energy model that it will produce as much renewable energy onsite as it will consume over the course of a year.

Most commonly, though not necessarily, this renewable energy is generated by solar panels. This definition for net zero energy specifies a year-long timeframe because solar panels produce more energy during the sunny summer months; excess energy not used immediately at the home is sold back to the utility and banked as a credit. In the winter, when a building is using more energy and the solar panels are producing less, this banked credit is applied to the bill.

Other forms of renewable energy fluctuate in their production based on weather and season as well. What matters to Built Green is that, in a year, the building has produced as much or more renewable energy than it has consumed.

Why?

Net zero energy homes have a significant role to play in addressing the climate crisis. According to the Drawdown solutions to reverse global warming, net zero energy buildings are one of the 100 important strategies. Even in Seattle, where homes receive carbon neutral electricity from Seattle City Light, net zero energy building has the potential to reduce greenhouse gas emissions by freeing up electric supply for transportation, which accounts for 64 percent of the city’s emissions. According to Built Green’s post-occupancy study, 4-Star homes save enough electricity to power an electric vehicle for a year. Obviously, the potential from net zero energy homes is even greater! Buildings have the ability to help clean the transportation sector through renewable electricity production.

On top of the environmental benefits, net zero energy homes also signify comfort and quality. Because these types of projects are not yet the norm (though we hope that soon they will be!), the designers and builders are putting extra thought into them and are often using some of the best examples of homebuilding technology and methods there are. The final product will be more comfortable thanks to the home’s efficient envelope and controlled ventilation. Residents of Built Green certified net zero energy homes have expressed their delight at how comfortable their homes are. And remember how credit for excess energy is banked by the utility? Well, that means residents’ electricity bills might even be negative—in other words, the utility will pay them!

Hopefully you’re convinced that net zero energy homes are a great thing, but why is the label itself important? We want to better support net zero energy building and spread the word about its benefits. At the present moment, it is a minority of builders doing these projects and we feel their accomplishments should be broadcasted. Not only will spreading the word acknowledge their hard work, but we believe it will help accelerate a market transition that is already happening and we would like to speed along.

The exterior of the house showcases local materials chosen for their durability and style. An 8.9 kW solar array brings the home close to net-zero annual energy consumption. The garage has been pre-wired for an EV charger. The attractively landscaped lot uses all native plants and bucks the suburban tradition of a water- and chemical-consuming lawn.

Passive solar features make the interior light and bright. The mini-split heat pump, SIPS walls, triple-paned windows, and the super-insulated slab and ceilings help keep the home comfortable year-round. The concrete slab was polished and sealed, requiring no additional flooring materials on the lower floor. WaterSense certified plumbing fixtures were used throughout to reduce water consumption without sacrificing functionality.

Built Green Highlights

Site and Water

• No lawn
• Landscaped with native plants
• Hydro-zoned landscape design
• All WaterSense-certified plumbing fixtures

Energy Efficiency

• EnergyStar certified
• Mini-split heat pump
• HERS score = 11
• 8.9 kW solar array
• All LED lighting
• Triple-paned windows

In the shadow of a mature tree canopy, Model Remodel’s contemporary home combines Northwest living with Mediterranean pattern and colors. This Built Green 4-Star certified home recently was awarded a 2023 REX Award for Green Remodel. The 1950s home was fully remodeled, including a 2nd story addition for a primary suite. Integration of indoor spaces with the natural environment was a key element to its redesign. The open floor plan with generous windows and glass doors creates a front-to-back view through the entire home, and easy access to its extensive outdoor activity spaces. Abundant with natural light and worldly décor, this playful remodel of a classic midcentury modern property made air sealing, eco-conscious materials, and green certification a priority.

Achieving an improvement of 29.3% over Washington’s 2015 energy code, an airtightness blower door score of 2.94 ACH, and a 4-Star Built Green rating, the home is comfortable all year round. The ductless multi split system in the bedrooms provides efficient heating and cooling using ceiling mounted cassettes, making it so you hardly know the system is there. A combination of rigid foam board and caulked foam were used to achieve such an airtight tight seal of the older home. Spot ERVs provide fresh air, while recovering temperature and moisture. A centrally located ducted system provides optimal comfort in the vaulted-ceiling open floorplan of the home. In-floor heat radiant heat in the bathroom floor tile offer additional comfort.

Above-code fiberglass windows and doors provide tons of natural light, eliminating the need for electrical lighting during daytime hours. LED lighting is used at night. A beautiful nano door and pocket window in the kitchen can be easily opened for an indoor-outdoor living environment. Low-VOC finishes on the flooring and shelving, plus no-VOC interior paint, keep air quality excellent.

Increasing the functionality of the home’s existing living space two rooms were redesigned into flexible multifunctional spaces. One area has a built-in murphy bed that can be pulled down for overnight guests, and another room features a sliding partition wall that can separate one room into two functional spaces.

One of the most obvious décor choices in the home is the Mediterranean-style patterned tile, which was salvaged from previous jobs and used here for multiple backsplashes and bathrooms. Cork flooring was used in multifunctional rooms to enhance comfort and warmth. It’s the patterned tile and flooring that bring color and vibrancy to a neutral paint palette. Lighting, cabinet hardware and décor are all sourced from the homeowners’ worldly travels, giving the home unique personality. Large 55 foot glulam beams effortlessly transition between indoor and outdoor evoking the tall trees on the property. Additionally, reusing the existing concrete foundation and basement, and fireplace, preserved and reduced embodied carbon emissions that would have been emitted had the home been torn down, rather than remodeled. A recycled content metal roof protects this home for the next century of its lifecycle.

Before/In Progress

After