Whatcom County Net Positive Home

Whatcom County Net Positive Home

This Built Green Five Star home in Whatcom County was selected as a Department of Energy 2019 Housing Innovation Award Winner!

The house is weighted south, toward the sun. With both asymmetrical roofs; longer to the south for solar build-out and a preponderance of south glazing for wintertime passive harvesting, the windows are appropriately shaded, with regionally appropriate eaves and porches, against summertime overheating.

The gross footprint of the house is rectangular, stretched with the long-axis running east-west to maximize space available for solar harvest on roofs and south wall, with much smaller east and west walls which overheat as they take the full force of the sun in summer. The slab-on-grade floor is finished to be left exposed and imparts a visceral, cooling, underfoot mass.

The slab also houses in-floor hydronic heating and radiates warm comfort during the long winter season, which, like all the seasons, can be felt and seen keenly in this house though the diversity of landscape views.

The home also features an open floor plan, with no wasted hallway space. The living area loft provides a sense of grandeur, but the modest-sized bedrooms and bathrooms require less energy and provide balanced efficiency.

SPECS/FEATURES

  • 2707 Square feet (conditioned)
  • 4 Bedrooms
  • 2.5 Baths
  • SIPs construction
  • 10.066-kW Solar
  • Triple-pane windows
  • Air-to-water heat pump
  • In-floor hydronic heating
  • Heat Recovery Ventilator
  • Electric car-charging
  • Low- or no-VOC products sourced throughout.
  • Wood posts, beams, counters, interior and exterior trim details milled on site from local timber

Photos by Scott Miller, Elevate Pro Photo

Toomes’ Bellingham Affordable Net-Positive Home

Toomes’ Bellingham Affordable Net-Positive Home

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

Clifton

Nicknamed the PowerHouse, this house 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.

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.  

 

Specs

  • 2,700 square feet,
  • 3 bedrooms, 2 bathrooms
  • 1st floor aging-in-place
  • Double height living/dining room
  • Powers itself and two electric cars, for net-zero emissions, over the course of a yearUses 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
  • Radiant-heat floors
  • 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

  • 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

Montlake Modern

Montlake Modern

After more than two years of looking at dozens of houses, putting down multiple offers on several properties, and just not being able to find exactly what they wanted, Relja and Yoojin decided to build their own house. With two architects in the family, it probably wasn’t very surprising.

The modern, positive-energy home they designed meets all its own energy needs while also powering an electric car. 

Both Relja and Yoojin work in the technology sector, and building their home with the most advanced materials was important to them. However, after receiving bids from other builders, they weren’t sure their dream home would be within their price range. After teaming up with TC Legend Homes, they found that building with advanced materials, such as structural insulated panels (SIPs) and insulated concrete forms (ICFs), could actually fit their budget.

In keeping with the high-tech concept, the house includes the latest in home automation to further reduce energy requirements. Heating, cooling, and the LED lights are all controllable through wifi. Even the master shower has a feature that prevents the water from turning on until the desired temperature is reached. The owners are looking forward to writing their own apps to help automate the house.

Features

  • Fresh air system utilizing HEPA filtration

  • Storm water managed with pervious concrete

  • Triple-pane windows

  • Zoned radiant heat powered by an electric heat pump

  • All-electric heat and appliances, including an induction cooktop

  • Car charging station in the garage

Press

Energy.gov
DOE Tour of Zero: Montlake Modern by TC Legend Homes

Green Building Advisor
Modern Dream Home is Energy-Positive

Curbed.com
Modern Marvels: Net-Zero Montlake Modern House Keeps It in the Family

Family photos courtesy of the homeowners and Katie Blanch Photography.