Is sustainability important to you? How about a home that produces the same amount of energy as it uses each year?
This project began with a strong desire to achieve a high level of energy efficiency in a modest footprint, 3-bedroom home. As a NetZero energy home, the building produces, on-site, the same amount of energy as it uses in one year, resulting in a net annual energy usage of zero. To achieve this goal, space heating demand was reduced through a careful analysis of the program and how it best related to the site, resulting in a compact and efficient floor plan which maximized views of the valley below and capitalized on the solar heating potential of the ample south-facing glazing.
Great care was given to selecting the high-efficiency technology which powers the electric lighting, kitchen appliances, and air circulation equipment. These systems work in tandem to reduce the overall energy consumption of the home through features such as occupancy sensors and an intelligent home automation platform.
Heat loss through the building envelope was greatly reduced through a super-insulated double-wall exterior envelope system with further thermal bridging and heat loss being reduced through advanced framing techniques and exceptional air sealing.
Features: 3 bedroom, 2 bath • Solar panels • Rain water collection • GeoSpring hybrid electric hot water heater • Mini split whole house heat pump and heat recovery system
Our client was an engineer and very interested in the science and technology behind making a net zero energy home.
He was involved in selecting the elements used, all the way from how solar power input was monitored, to wall construction, and how we daylighted and shaded the house.
He also wanted to do a lot of farm production, both animals and plant food.
The house and the detached garage provide two different functions. The roof of the house is sloped away from the south to allow full passive solar exposute to the wall. The roof of the garage has the solar panels and therefore slopes towards the south.
Phase change materials are used in the southern wall of the house. When heated by the sun, the substance within the double walls becomes a liquid, but when the wall cools at night, it turns into a solid. This change from liquid to solid releases heat, warming the home at night. There is also a high efficiency wood stove to add additional warmth.
Other elements include a heat recovery ventilator, ductless mini splits, heat pump hot water heater, double wall construction with 2″ void in between, overhangs and canopies to protect from the sun in Summer but allow solar gain in the Winter when the sun is more horizontal.
The house is build at the top of a hill overlooking the terraced gardens and farm land below.
Cost for construction is higher than a standard home, but it is compensated in the long run with energy savings. The objective of a Net Zero Energy building is not only environmental , but economical as well.
Documentation had to take into account the requirements to produce the net zero energy, including double wall construction and phase change materials.
The other challenge was the steeply sloped property requiring a stepped up level inside.
Our in-house permitting technician was involved throughout the project as an advocate for our client, making sure the unique requirements for this house were approved.
A few of these requirements include:
The driveway had to be relocated and a berm removed for visibility and safety when entering the road.
Unique double wall construction was used on exterior walls for a full thermal break between the outside and inside walls.
And unique Phase Change materials for passive heating were needed.
But, because of our experience and relationship with the Whatcom County agencies, it all went smoothly.
Our architect and design technicians maintained close collaboration with the contractor to assure proper construction of this unique home.
Part way through construction, before drywall was installed, Sustainable Connections gave a public tour so people could view the ventilation, insulation, and other factors unique to zero energy living.
Construction: Bellingham Bay Builders Photography: Jim W. Smith