Electric Vehicle Charging

Bellingham Affordable Net-Positive Home

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Built by the TC Legend Homes/Powerhouse Designs team. We design and build. With a standard palette of materials & details that have been chosen, tested & refined over many houses, there is no confusion for the crew. The draftsman, engineer, and crew are consistent through all our projects, so everyone has done this system before.

Key Features:

  • Positive Energy – produces enough electricity to also power an electric car.

  • Energy Star, EPA Indoor airPLUS, and 5-Star Built Green Certified.

  • Honorable Mention in the Affordable Category of the 2018 US Department of Energy Housing Innovation Awards.

  • The home is oriented for both passive & active solar performance by facing south, as a rectangle with the long side (26’) running from east to west. The home is outfitted with an 8.1kw photovoltaic system.

  • Energy envelope includes structural insulated panels (SIPs). The 6.5" Neopor R29 SIPs panel walls are locally made in Washington. Designed & engineered to reduce cold bridging by minimizing structural lumber & maximizing use of foam splines to connect panels. Shell is air sealed with triple beads of mastic at all joints and panels additionally taped at all joints. RIM joist insulated with R30 spray-foam at floor systems. Perfect rectangle box adds simplicity to construction & reduces corners & thus cost & air leakage.

  • 4" Extruded Polystyrene (EPS), a low VOC foam (R20), is used under-slab. The concrete slab-on-grade is exposed and is effectively a free finished-floor and a functioning thermal mass.

  • The heat recovery ventilator (HRV) is a Zehnder Comfo-air 200 which can scavenge 95% of the heat from the outgoing dirty air. Running through a class 4 filter (merv7/8) at between 29 and 118 cubic feet/ minute (cfm), the unit ventilates the whole house, extracting moist air from bathrooms/utility spaces, bringing fresh air into living spaces.

  • Energy Star appliances including a Geospring 50-gallon heat pump-powered hot water heater.

  • Stormwater from the roofs is infiltrated on-site using splash blocks below the gutter downspouts.

  • Home Energy Rating System (HERS) Index is negative 25!  (A typical new home has a rating of + 62).

Bellingham Power House

Bellingham Power House Exterior

There's nothing we love more than building overachieving homes. This remarkable home not only produces enough solar electricity to meet its own energy needs, but it produces surplus power to charge two electric cars.

Nicknamed the Power House, it is the first of its kind in Whatcom County. 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 will produce more power than the house uses, with enough of a surplus to power two electric cars through on-site charging stations.

The house qualifies 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.

Perhaps more remarkable than the home’s efficiency is its modest price tag. Shared by two couples and three children, the 2,700-square-foot custom home cost under $150 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 and passive solar design, highly efficient heat pump, solar hot water, and a solar PV array using Bellingham-built ITEK modules, this one-of-a-kind house has no electrical bills (other than the monthly service charge for this  grid-tied system) and costs nothing to heat. No oil, natural gas, or other fuels are used. 

This home shows that cutting-edge energy efficiency technology can actually be made affordable by eliminating entire categories of expenses, like heating and gasoline bills. And if one house can be shared by two families, expenses are decreased for both.

Specs

2,700 square feet, co-housing duplex for 2 families, 2 stories, 3 bedrooms, 3 bathrooms, 3 multi-purpose rooms: loft, rec room and sunroom, semi-covered deck, covered parking, acid-stained concrete slab foundation, radiant-heat floors, exposed beams, Hardie plank & milled cedar siding, metal roof, solar hot water, 9.9 kW solar array, 2 electric car charging stations.
 

  • Powers itself and two electric cars, for net-zero emissions, over the course of a year

  • Uses a 9.9kW photovoltaic system (half power goes to the house, other half powers two cars)

  • Envelope includes structural insulated panels, insulated concrete forms, and 4” foam under slab

  • Heat and hot water provided by a solar hot water collector with an air-to-water heat pump backup

  • South-facing high solar gain triple-pane windows and solar absorbing concrete floors

  • Utilizes the most energy-efficient appliances and lighting available on a budget

  • Collects rainwater for all outdoor water usage and utilizes low-flow fixtures indoors

  • Provides housing for four adults and three kids with enough garden space to feed both families

  • Budget under $150/SF includes all development costs except land (built on an infill lot in the city)

  • Northwest Energy Efficiency Alliance is monitoring home for US Department of Energy pilot program

  • Fresh air provided by heat recovery ventilator and earth tube combo system

  • HERS rating is -15