Located on a portion of a subdivided, family property, this 2,614 SqFt Bellevue, WA home is a beautifully built house that helps to foster multigenerational ties and community. With a 5-Star Built Green rating, EPA IndoorAir Plus certification, and a Net Zero Energy certification, this award-winning TC Legend home is an example of the influence and success of the Build Green program. With a specific focus on indoor air quality, this home employs a new ventilation and air filtration system, helping to make it a safe and comfortable environment for its occupants.
Built with passive and active solar needs in mind, the two-storey house faces south. Numerous triple glazed Vinvltek windows on the south side provide passive heating and light within the home. These windows and others throughout the house are coupled with white interior paint to help provide significant daylighting and reduce energy demand from the 100% LED home lighting. The home also employs a 12.87kW photovoltaic system, producing enough power to make the home net positive and power an electric vehicle. With a shell system constructed from 6.5” SIPs walls, 10.25” SIPs roof, 4” foam under the slab-on-grade, ICF form slab-edge stemwalls & U 0.18 average triple pane windows, this house has a tight envelope, helping to reduce energy consumption.
The three-bedroom, two bath house is meant to allow the occupants to age in place with the kitchen, main living space, a bedroom and bathroom, and ADA compliant doorways on the first floor. The state-of-the-art fresh air system includes a Zehnder 350 HRV, Zehnder Comfopost inline heating/ cooling coil, and HEPA air filtration system. This system allows for fresh, filtered air to enter the home throughout the day and to be increased when needed, such as when the kitchen hood fan is drawing smoke out of the kitchen during cooking. This fresh air system keeps the indoor air clean, reducing particulates in the air, even when the outdoor air quality is particularly poor such as during a summer forest fire.
Overall, this home is a comfortable, clean, and net positive building, allowing the homeowners to be happy, healthy, and confident in the knowledge that their home is serving their needs and protecting the environment in the process. The BuiltGreen Certificate of Merit and 5-Star rating this home received help to reinforce this knowledge due to the standard of excellence required of BuiltGreen certified homes.
Built Green highlights:
SITE & WATER
Long term erosion reduction strategies in place
Over 70% of building site left undisturbed with preservation of trees and native vegetation
Stormwater infiltration system catches all stormwater from the site and the uphill grandparents house, mitigating flow
Approx. 50% of the lot is turf grass
Watersense certified fixtures and low flow fixtures and toilets
Rainwater collection ready
ENERGY
Net-Positive Home with a HERS score of -22 and extra power to serve an electric vehicle
12.87 kW roof PV array
Substantial envelope insulation lowers heating requirement: R-30 walls, R-49 roof, R-20 under slab, R-24 slab-edge, average U-0.18 windows
Triple-paned Vinyltek Windows with u-values from 0.15-0.22
Passive Heating Design strategies utilized
Chiltrix Air-to-Water Heat Pump for heating and domestic hot water with COP of 3.92
AeroBarrier air sealing and blower door results of 0.47 ACH50
100% LED lighting
All Energy Star certified appliances
Energy Star certified
DOE Zero-Energy Ready certified
HEALTH & INDOOR AIR QUALITY
Indoor AirPLUS certified
Solid wood cabinets with Low-VOC finish
All Low-VOC paints, adhesives, and sealants
No gas-burning appliances in house
HEPA Air Filtration System
Zehnder HRV with ComfoPost
MATERIALS EFFICIENCY
Graphite SIPS for exterior walls and ceilings
ICF foundation walls
85%+ of waste recycled
Locally produced lumber, SIPs, concrete, cabinets, doors, and siding
Exterior cedar posts constructed form telephone pole MFG waste
Leftover materials moved to next job
Solid wood, domestically grown interior doors and trim
Locally produced Vinlytek windows
Location: Bellevue, WA Star Level: 5-Star, Net Zero Energy Label Checklist: Single Family/Townhome New Construction Verifier: ECoe Company
Site and Water: 109 Energy Efficiency: 239 Health and Indoor Air Quality: 126 Materials Efficiency: 109 Total Score: 629
TC Legend Homes built this 2,463-ft2 home in Seattle, Washington, to the performance criteria of the DOE Zero Energy Ready Home (ZERH) program. The two-story home has SIP walls and triple-pane windows for draft-free construction and high insulation values.
Project Data
Name: 19th Avenue
Location: Seattle, WA
Layout: 4 bdrm, 2.5 bath, 2 fl, 2,463 ft2
Climate Zone: IECC 4C, marine
Completion: May 2016
Category: custom for buyer
Modeled Performance Data
HERS Index: without PV 44, with PV -2
Projected Annual Energy Costs: without PV $1,053, with PV $25
Projected Annual Energy Cost Savings (vs home built to 2012 IECC): without PV $811, with PV $1,889
Projected Annual Energy Savings: without PV 9,453 kWh, with PV 20,993 kWh
Added Construction Cost: without PV $0
When a net-zero-energy home can be built at a cost on par with traditional construction, everyone wins. TC Legend Homes is helping to usher in a new era of green construction in which home owners don’t have to choose between cutting-edge efficiency and staying on budget.
“Over the last decade, we’ve developed practices that allow us to build net-zeroenergy homes for the same price as traditionally constructed homes. Sometimes, we are able to build them for even less,” said TC Legend Homes’ owner and lead Ted W. Clifton, Jr.
“We know we are doing something right because our services are in high demand,” said Clifton, who is headquartered in Bellingham, Washington, but also builds in the Seattle area.
One way TC Legend Homes is achieving net zero is by building to the high performance criteria of the U.S. Department of Energy’s Zero Energy Ready Home program. DOE has honored the builder with four Housing Innovation Awards since 2013, including a grand award in 2014 in the affordable category and a 2016 award in the custom home category. The 2016 award-winner is a two-story, 2,463-ft² home located next to another TC Legend Home on an urban infill lot in Seattle.
The high-performance features of this home, combined with the 9.5-kW PV system and solar water heating, help the home achieve a Home Energy Rating System (HERS) score of minus 2. That equates to calculated annual utility costs of $25 (counting service charges) or enough electricity to power the all-electric home. If the home performs better than calculated, it will cover the power for the electric car charging station in the garage as well. Even without the PV, the home would achieve a HERS score of 44, far better than the HERS 80 to 100 of typical homes.
Clifton is used to getting such scores. He has been certifying homes to the DOE Zero Energy Ready Home program since 2013. His previous winning homes have HERS scores ranging from -12 to 13 with PV or 34 to 43 without PV. Clifton has committed to building all of his future homes to the program.
The DOE Zero Energy Ready Home program requires homes to meet all of the requirements of ENERGY STAR Certified Homes Version 3.0 and the U.S. Environmental Protection Agency’s Indoor airPLUS program as well as the hot water distribution requirements of the EPA’s WaterSense program and the insulation requirements of the 2012 International Energy Conservation Code. In addition, homes are required to have solar electric panels installed or have the conduit and electrical panel space in place for future photovoltaic panel installation.
The 2016 award-winning home was situated on the northern edge of the lot to maximize southern exposure. “Our houses are designed from the ground up to take advantage of the sun. A passive solar layout like the one in this house means lots of windows facing south and few facing north,” said Clifton. The long axis of the house is east to west to allow for maximized solar exposure for the PV and solar hot water systems and for passive solar heating. High-quality triple-paned, vinyl-framed windows were located on the south side of the house to maximize solar heat gain. The builder polishes and stains the concrete floor slab to use as the finished flooring; its thermal mass absorbs heat from the sun during the day and slowly releases it at night to provide beneficial passive solar heating.
Structural insulated panels (SIPs) were used for the walls and roofs. “We chose SIPs for their excellent insulation values, airtightness, and ease of construction,” said Clifton. SIPs consist of two layers of OSB sandwiching a layer of rigid expanded polystyrene foam. They arrive from the factory as 4x8-foot sheets or precut for doors and windows as required for each wall. Clifton uses locally made panels that come precisely cut, allowing for fast construction, a strong, airtight shell, and practically zero jobsite waste. The TC Legend Homes crew is trained in SIPs construction, which helps assembly go smoothly. Clifton has used SIPs ever since he began constructing homes with his father, Whidbey Island builder and designer Ted L. Clifton, while in high school. Ted Clifton Jr. is on site daily to oversee every step of the TC Legend home construction process, allowing for any problems to be quickly fixed.
For the winning home’s walls, Clifton specified R-29, 6-inch SIPs that are glued and taped at all interior and exterior joints. The panels are covered with house wrap that is overlapped and taped to serve as a drainage plane under the fiber cement siding. The roof decking consists of R-42, 10-inch SIPs, also taped at all interior and exterior joints. The whole roof deck is covered with self-adhering ice-and-water shield, which provides a weather-resistant layer under the asphalt shingles. There is no attic in the home. Because the SIP panels provide the insulation and roof decking in one layer, all of the home’s upper-floor rooms can have vaulted ceilings.
The home has a slab-on-grade foundation with stem walls made of insulated concrete forms (ICFs) that wrap the sides of the slab in R-23 of insulation while an R-20 layer of rigid foam covers the ground under the entire slab. Seams are taped and the rigid foam layer serves as the vapor barrier between the ground and the home.
The concrete floor slab contains radiant floor loops. Water for the radiant floor heating is provided by the roof-mounted evacuated tube solar hot water system and by an ultra-efficient air-to-water heat pump with a coefficient of performance (COP) of 4.5. These systems also provide domestic hot water. The heat pump’s indoor unit is centrally located on the main floor. Low-flow fixtures help cut water usage.
ENERGY STAR-rated appliances also reduce water and energy usage. All of the home’s lighting is provided by LEDs, adding to energy savings. The home was assessed by a home energy rater per DOE Zero Energy Ready Home requirements and showed air leakage of only 0.60 air changes per hour at 50 Pascals. That’s equivalent to the Passive House Institute U.S. Standards and three times tighter than required by the newest energy code. (The 2015 International Energy Conservation Code requires 3 ACH 50 or less.)
To provide good ventilation for the home, the builder installed timered exhaust fans to provide spot ventilation in the four-bedroom home’s 2.5 bathrooms. The range hood fan is timer controlled with a 200-cfm fan that pulls fresh air into the home through a vent located downstairs on the north side of the home. Both fans can be set to come on for balanced ventilation during the day and for night-time cooling in the summer.
Use of low- and no-VOC paints, finishes, and flooring and good moisture management practices like site grading and drainage were among the measures the builder installed to comply with the requirements of the EPA’s Indoor airPLUS checklist.
Home Certifications
DOE Zero Energy Ready Home Program, 100% commitment
ENERGY STAR Certified Homes Version 3.1
EPA Indoor airPLUS
In a “green” market like the Pacific Northwest, marketing DOE Zero Energy Ready Homes is easy. TC Legends has found it gets more than enough customers through these avenues: 1) referrals from other customers; 2) TC Legends’ website; 3) TC Legends’ presence on other websites, for example the DOE Tour of Zero and Housing Innovation Awards sites; and 4) participation in the annual Northwest EcoBuilding Guild’s Green Home Tour.
“Because TC Legend Homes builds custom homes, most of our potential customers approach us already wanting an energy-efficient home. We educate our customers about how our homes are different from most houses and about how we achieve net-zero energy and positive energy in the homes we build,” said Clifton. “By conserving as much energy as possible, these homes will be able to offset more than 100% of their electricity usage with the roof-sized solar electric systems.” said Clifton.
By value engineering and fine-tuning their processes, TC Legends is able to achieve zero energy at surprisingly low cost. “We only do net zero energy construction, and for less than most builders in the area do regular construction. We average $200/ft² including solar,” said Clifton.
Key Features
DOE Zero Energy Ready Home Path: Performance.
Walls: R-29, 6" SIP taped at all interior and exterior joints, fiber cement siding.
Roof: R-42, 10" SIP taped at all interior and exterior joints. Ice-and-water shield, asphalt shingles.
Attic: None.
Foundation: R-23 ICF stem walls, R-20 rigid foam under slab.
HVAC: Evacuated tube solar hot water and 4.5 COP air-to-water heat pump for in-floor radiant hydronic heat.
Hot Water: Air-to-water heat pump, COP 4.5.
Lighting: 100% LED.
Appliances: ENERGY STAR refrigerator, clothes washer, range hood; induction cooktop.
Solar: 9.5-kW PV, evacuated tube solar hot water.
Water Conservation: Low-flow fixtures; centrally located water heater.
Other: Low-VOC paints and finishes.
Electric vehicle charging stati
The U.S. Department of Energy invites home builders across the country to meet the extraordinary levels of excellence and quality specified in DOE’s Zero Energy Ready Home program (formerly known as Challenge Home). Every DOE Zero Energy Ready Home starts with ENERGY STAR Certified Homes Version 3.0 for an energy-efficient home built on a solid foundation of building science research. Advanced technologies are designed in to give you superior construction, durability, and comfort; healthy indoor air; high-performance HVAC, lighting, and appliances; and solar-ready components for low or no utility bills in a quality home that will last for generations to come.
For more information on the DOE Zero Energy Ready Home program go to https://energy.gov/eere/buildings/zero-energy-ready-home
There's nothing we love more than building overachieving homes. Our latest project will not only produce enough solar electricity to meet its own energy needs, but it will produce surplus power to charge two electric cars: a Tesla Model S and a Nissan Leaf.
Nicknamed the Power House, it is the first of its kind in Whatcom County and one of few such homes in the world.
Perhaps more remarkable than the home’s efficiency is its modest price tag. Shared by two couples and three children, the 3,000-square-foot custom home will cost under $110 per square foot to build, significantly less than most other residential construction projects in Bellingham.
With its airtight shell, structural insulated panel (SIP) construction, numerous south-facing windows, highly efficient heat pump, and approximately 10,000-watt solar panel array (built by Bellingham’s own iTek Energy), this one-of-a-kind house has no electrical bills and costs nothing to heat. No oil, natural gas, or other fuels are used.
The home sends power to the city’s electrical grid when the sun is out and draws it during the night or on cloudy days. (Contrary to popular belief, the Pacific Northwest is an excellent place for solar.) Averaged over the entire year, the panels produce more power than the house uses, with enough of a surplus to power the two electric cars through on-site charging stations.
The house will qualify for a one-time federal tax credit of approximately $10,500 and Washington State solar production credits of approximately $5,000 a year until 2020.
The owners are also saving money by teaming up with friends. The Power House is being built under a unique co-ownership agreement between the owners of TC Legend Homes, Ted Clifton and Rachel Lee, and their longtime friend Eric Murphy.
The house features two residences, each with its own private entrance, connected by a 700-square-foot common area.
Eric Murphy, a professional mountaineering guide who leads trips around the world, says he is especially enthused by the climbing wall and home brewing area that will be integrated into the home’s shared space.
The house has a system to harvest rainwater from the roof into a 3,000-gallon cistern, which also helps to trim the home’s utility bills.
The Cliftons will be irrigating their eighth-acre vegetable garden using only water they collect.
The home will show that cutting-edge energy efficiency can actually be affordable. By eliminating entire categories of expenses, like your home heating bill, your electrical bill, and now even your gasoline bill for your cars, then you can really see how this idea can pay off. And if one house can be shared by two families, you come out even further ahead.
Bellingham’s first positive-energy house will be completed early this spring.
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