The project is located near many public transportation routes, sits three blocks north of the Burke-Gilman trail and, with a Walk Score of 92, daily errands do not require a car. The building offers bike storage and a repair station to further incentivize tenants to ride their bikes, thus reducing dependency on cars and the project’s overall carbon footprint.

A large factor contributing to the project’s overall sustainability is its efficient use of space. Despite their small size (323 square feet on average), each studio includes a built-in Murphy bed, shelving, and desk. These fundamentals allow the tenant to create extra living space when they’re awake while still maintaining density in a fast-growing neighborhood.

To meet Built Green 4-Star standards and reduce the building’s overall energy consumption, the project focused on energy efficiency via domestic hot water, appliances, and lighting. Two high-efficiency gas tankless water heaters with recirculation pumps service the building, and water is sparingly used via low-flow plumbing fixtures. Each unit’s kitchenette comes with ENERGY STAR appliances as well as in-unit laundry and quiet, energy efficient ventilation fans. LED lighting is used throughout the entire building to further reduce the amount of energy needed for each unit and optimize building security. In addition, an array of solar panels was installed to help offset some of the energy consumed from plug loads, unit heating, appliances, and more.

Built Green Highlights

Site and Water

• No turf grass and drought-tolerant landscaping.
• Low-flow plumbing fixtures.
• Partial green roof with amenity space.

Energy Efficiency

• Energy consumption reduced by more than 28 percent compared to code.
• ENERGY STAR appliances and LED lighting.
• 1.7 kW of solar panels.

Freehand Studio Architects engaged with the homeowner to create a multigenerational site for their family with the addition of this backyard cottage. The design features a bedroom and bathroom on each floor, as well as flex space and 2nd story deck. The soaring double height great room provides an airy, light-filled atrium which belies the 1000 SF floor area.

Lowering the Upfront Material Emissions

Using the BEAM tool, Targa set out from the beginning to use low embodied carbon materials wherever possible, and ultimately achieved a 30% reduction in material carbon emissions. The home is framed with reclaimed lumber provided by Sledge Seattle—a company that deconstructs homes that are otherwise slated for demolition. The centuries old Fir that comes out of these homes is dense, dry, and ready to serve another 100+ years. BEAM was utilized to show the team that using blown-in cellulose cavity insulation and cork exterior insulation makes a major impact on lowering the total kg CO2e for the project compared to the typical fiberglass and foam. Other notable decisions include using LP SmartSide lap siding (an engineered wood product) instead of the typical Hardie plank, as well as generally substituting wood based products for foam and plastic wherever feasible.

Exterior cork insulation

Dark color of reclaimed fir

While framing the home, the team was continually stunned by the tight grain of the reclaimed old growth Fir. The team could not let any of it go to waste, so the lead carpenter Matt Kull fabricated a custom end-grain butcher block countertop out of framing lumber. This centrally located focal point provides a visible connection to the invisible bones of the home.

Supplying Fresh Air in an Air-Tight Home

Superior Indoor Air Quality was a priority for architect and builder and the first step towards this is airtight construction. Starting with a fully taped sub-slab vapor barrier, the air barrier then wraps under the bottom plates which are sealed with sill seal foam and Contega HF flexible adhesive caulk. The bottom of wall is also sealed to the concrete stem wall using Siga tape for a belt & suspenders approach at this critical joint. Zip System sheathing with taped seams on the walls and roof form the primary air barrier above grade. The unvented roof is framed using a unique over-roof assembly (also known as “Monopoly Framing”) where rafter tails are applied on top of the structural roof sheathing after the roof sheathing and roof/wall joints are air sealed with tape. Rigid foam is then installed on top of the roof sheathing providing continuous insulation that keeps the sheathing above dewpoint at all temperatures. This high performance assembly avoids spray foam and is a much more durable and forgiving design.

The high glazing ratio can be a detriment to energy efficiency, so the team chose Vetta windows to mitigate this. These European made triple pane tilt/turn windows are made from FSC wood and clad in an aluminum exterior. Although the team found these to have a large carbon footprint, the beauty and fantastic durability were offsetting factors.

The team runs a preliminary blower door test just before insulation to identify and address any problem areas. This home scored a final blower door score of 0.02 CFM/SF shell (0.35 ACH50) placing it well below the PHIUS passive house air tightness standard. With extreme air tightness comes a necessity for ventilation and this home uses a Zehnder Energy Recovery Ventilator (ERV) running continuously to provide fresh filtered air and exhaust stale air. Low-emitting interior finishes are the final piece in a healthy IAQ home.

High Performance Systems and Fixtures

Heating and Cooling are primarily from two ductless minisplits, with backup bedroom heat from Ducoterra radiant panels on the ceiling. Hot water is made by a SanCO2 split system heat pump water heater. This unit uses CO2 refrigerant (much friendlier to the atmosphere) and runs at an astounding efficiency to quietly provide hot water year-round without electric resistance. A heat pump clothes dryer is also an efficiency upgrade and doesn’t require a penetration through the wall for exhaust. An induction cooktop and LED lighting round out the specs for the all-electric home.

To provide energy usage feedback to the occupants Targa installed a Leviton Smart LoadCenter electrical panel which reports usage for each individual circuit in the home to a smartphone app. Paired with the homes 3.6kW Solar PV array, occupants will be able to live as close to net zero as possible.

Low flow plumbing fixtures were chosen throughout including ultra-efficient Niagara 0.8 gallon per flush toilets. The team also chose to infiltrate rainwater on site using a drywell which wasn’t required by the city. Fireclay tile, Valinge engineered wood flooring, and Paperstone countertops were chosen as sustainable, functional, and attractive finishes.

The dead-end alley was named after Edson “Dad” Abbott, who brought Dream Theater to Sedro-Woolley in the 1930s, ushering in and fostering a sense of community for the town. To honor this history, the end of the alley provides a new “Dream Theater” as a gathering spot for movies, music, and other outdoor events. This feature proved to be a crucial community amenity during the COVID-19 quarantine, allowing community members to gather outside with masks and plenty of distance to safely enjoy movies together and share stories around the firepit.

Creating homes that provide for a flexible lifestyle was a key component of the project. The ground floors are fully accessible; they are set up for a future kitchen, have private entrances, and include a bathroom with an accessible shower. City zoning mandated commercial use on the ground floor, but banks don’t typically like mixed-use homeowner mortgages. The solution was to build individual structures that meet single-family criteria for a traditional homeowner mortgage loan, but also satisfy the requirements of the land use code. The International Residential Code acknowledges these live/work units as single family. Despite being a novel idea in this town when first proposed, this last year has been a good reminder that reviving the old way of “living above the shop” has a myriad of benefits.

With a simple design and careful attention to construction details, Martha Rose Construction was able to achieve a HERS Index of -10 on each of the six live/work homes in this enclave in downtown Sedro-Woolley. This was accomplished through a variety of techniques, including the “Martha Wall,” excellent air sealing, beefed-up insulation, and careful attention to equipment choices. A 9.9 kW solar array tops each building. Martha shared that, “After living in my home for three winters, I’ve never used all of the electricity generated on the roof, even with charging an EV!” Construction materials were chosen for health, proximity to the job site, easy maintenance, durability and beauty. Hard surfaces were used on the floors and there is no crawl space. Plumbing fixtures meet or beat WaterSense criteria.

Despite the high percentage of impervious surface, 100% of the stormwater is managed on site. The city allowed the project to install a giant infiltration basin made of railroad ballast under the paved alley. The 160 yards of granite ballast provide the structure for the road while providing 40% voids to contain rainwater while it slowly seeps into the ground.

Homeowners benefit from the Marth Rose’s detailed focus on indoor air quality. Five fresh air changes every day, made possible with a very high efficiency heat recovery ventilator that runs continuously, is one leg of the healthy home strategy. During the 2020’s wildfire smoke-filled air, these homes were smoke-free. During the pandemic, these homes offered a higher level of protection because of the year-round conditioned fresh air.

Built Green Highlights

Site and Water

• 40% void infiltration bed below development manages 100% of stormwater onsite
• New landscaping emphasized native vegetation
• Existing vegetation that was removed was replanted or donated for reuse
• No turf grass
• Pesticide-free integrated pest management plan
• Low-flow plumbing fixtures
• High efficiency 0.8 GPF toilets
• Main floor is an accessible studio/commercial space

Energy Efficiency

• HERS index -10
• 120% better than code, Net Positive Energy!
• 100% electric, fossil-fuel free operations
• 9.9 kW solar PV on each unit
• EV charging ready
• Energy Star and DOE Zero Energy Ready Home certified
• R-20 sub-slab insulation
• Blown-in cellulose walls and ceiling (~85% recycled content)
• Blower door score of 1.2 ACH
• "Martha Wall" utilizes 1" of closed-cell foam under the exterior plywood for continuous thermal break

Health and Indoor Air Quality

• EPA Indoor airPLUS certified
• No carpet in the units
• No garages
• All paints, finishes, and materials are low-VOC and NAUF
• Roof overhangs of 24” and 36”
• Heat recovery ventilators with ECM motors

Materials Efficiency

• Deconstructed existing 600 SF house and reused onsite salvaged materials
• Used locally salvaged lumber for concrete forms, siding, and finish shelving
• Interior walls designed for flexible spaces
• Abundant use of local and regional materials
• Polished concrete slab floor
• Cork stair treads
• Metal siding installed
• Pantry with open shelves, cabinets, and counters using local, recycled materials and some steel
• Reclaimed diamond blocks for landscape walls