Sitting on a stunning 5-acre lot nestled into the woods and surrounded by wildflowers and berries, the Samish Solar Home is a resilient oasis for a growing family of mountain bikers and nature enthusiasts.

This 4 bedroom, 3.5 bath, 2,345 square foot single family residence was built for a young family in Bellingham, Washington. The primary goal of this home was to serve as the owner’s permanent residence, even as their needs change over time, while adding a layer of resiliency towards our changing climate. The home was designed to support a growing family, temporary or permanent aging parents, a home office, and ample storage for outdoor recreation gear in the 1,936 square foot garage. Samish Solar home also features an additional sunroom on the south side of the house to enjoy the sunshine year-round.

The home is built using a post and beam structural system in addition to structural insulated panel (SIP) exterior walls and roof. The double-height, vaulted ceilings in the living room provide excellent daylighting for current use, but a floor system and internal walls could be added in the future to transform this 4-bedroom home into a 5- or 6-bedroom home.

Sustainable Envelope & Mechanical Details

Working in conjunction with the graphite infused SIP walls and roof (R-29 and R-59 respectively), triple pane Vinyltek windows, an R-20 insulated slab-on-grade foundation and R-23.6 ICF foundation walls help complete the envelope of Samish Solar Home. Due to the sandwich design of SIPs, the envelope of the project started out very airtight, however in order to push the tightness even further and achieve an ACH of 0.27, Aerobarrier aerosol sealant was used to complete the air sealing. This project also features the tried-and-true TC Legend Homes HVAC model combining a Chiltrix CX-34, Fantech Hero 250, and rooftop solar. The CX-34 heat pump unit provides both domestic hot water and space heating/cooling through a zoned radiant hydronic system on the first floor and a fan coil unit on the second. These superior insulated materials coupled with our HVAC system and tight envelope create this high efficiency and high-performance home.

Climate Change Resiliency

With significant south facing windows and shading eaves, this home takes advantage of passive solar heating and cooling, which will help regulate the home’s temperature as summer and winter temps become more extreme. The triple pane, argon-filled windows also help to create a better barrier to the extreme outdoor temperatures. Since the roof will take the brunt of the solar heat, Cool Roof certified metal sheeting was installed to further prevent the home from overheating in the summer by increasing the albedo. The Fantech Hero 250 HRV provides the home with a constant flow of fresh air filtered through its built in HEPA filtration. This home maintains healthy indoor air quality even at the height of wildfire season, providing a safe haven for its occupants, friends, and family. The biggest resiliency feature of this home is the 28,000 gallon rainwater catchment system that supplies water for the fire suppression system and domestic water. The rainwater is filtered through a sediment filter, activated carbon filter, and UV filter to ensure it is fit for domestic use. The catchment system, which was required due to site water availability limitations, was significantly upsized in order to add resiliency. With the understanding that significant periods of drought are likely in the future, the larger catchment system will ensure adequate domestic water for the home and provide self-sufficiency in the future. Low-flow and water sense labeled plumbing fixtures also help to reduce water demands. The homeowners also opted to upsize the rooftop solar array to a 10.8kw system with Enphase microinverters. The solar system is battery ready for future resiliency additions and provides the home with more power than it needs, making the project net positive and allowing the owners to power an electric vehicle in the future. There is also plenty of roof area where additional solar could be installed if energy needs of the home change in the future.

Accessibility

In designing this home, it was important to the client that we future proof for aging parents who may need to utilize mobility aids and to ensure they, themselves, can grow old in the home. This meant designing with the essential spaces, such as the laundry room and kitchen, located on the first floor. All of the doorways were also widened to 3’ and the first-floor shower was made curbless to help ensure this home is functional in all phases of the owners’ lives. The unheated breezeway between the house and garage provides a central, stepless entry point and protection from the elements. This space also serves as a shoe removal area with a built-in bench and coat storage. At both the main entry and side entry, a stepless large, covered patio was installed, which can serve as a fantastic gathering area for everyone without any limitations. Lastly, in a less conventional form of accessibility, Powerhouse Designs will be adding Samish Solar Home’s premade plans to their website so others can build this home with a lower upfront design cost.

As the population continues to age rapidly the need for healthy, energy efficient senior living continues to grow. Eliseo, which provides independent or assisted living for seniors, made the decision to construct two new buildings with a total of 91 units in their existing complex located in Tacoma. These two new buildings both obtained a Built Green 4-Star certification on the 2017 new construction multifamily checklist using a variety of different green building strategies.

During the design and permitting phases of the project, the project team engaged with the verification team to ensure the project’s success by planning and brainstorming the credits they wanted to obtain throughout the checklist and changing specs as needed to align with their goals and vision. One example was finding the right drought-tolerant grass that would blend with the pre-existing landscaping and not create a stark visual contrast. Together the whole team was able to find the right mixture!

Other credits that were claimed to obtain certification was the use of low flow plumbing fixtures to minimize water used within the building; ductless mini-splits and Energy Star appliances to keep energy costs down; and low VOC products with indoor air-quality certifications to keep tenants safe and healthy.

In addition to the above-mentioned green building features, the project also utilized a lot of water management strategies. With the help of a building envelope consultant, they applied drainage mats around the foundation, fluid-applied doors and window flashing along with back dams, taped seams on their WRB, and installed a rainscreen under their siding. All these features were able to help them to obtain low air-barrier test scores (0.154 & 0.151CFM/SF @ 75Pa) that will not only result in lower energy bills but will ensure the building stays dry throughout the years to come.

While this Built Green certification is one of the first for the City of Tacoma, there is an expectation and hope that many more will follow as buyers and residents begin to recognize the value in sustainable building – not only economically through energy reduction, but also for their health and the wellbeing of the planet.