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

By framing their walls with two 2x4s, they have the flexibility to stagger studs so they do not align, reducing the potential for thermal bridging. Thermal bridging occurs when a more conductive material (such as a wood stud) provides a direct path between the cold outside air and the warm inside air. By staggering 2x4 studs, Dwell is able to break up that path with a cavity of insulation, which helps to minimize that transmission. They are also able to leave a gap between the two walls and change how thick their walls are.

For the Bagley projects, the walls are roughly 10 inches thick and completely filled with blown-in cellulose insulation. Having such a thick, well-insulated exterior wall makes these houses very quiet and easily able retain to heat or cold produced by the HVAC system.

Although the three houses are composed of two different projects, all three units are heated using ductless mini-split heat pumps, with Envi wall heaters as supplemental heat. Water heating is done via a hybrid heat pump water heater with a temperature-based recirc system. Since all of Dwell’s houses are 100% electric, homeowners can offset all their energy usage by adding solar panels; Dwell prewires for solar.

In fact, one of the Bagley houses included a 14.25kW solar system, which made the final HERS score -2. This means that the house produces more energy than it uses! This offset was possible by keeping the home’s loads (how much energy the home needs) low with Energy Star appliances, including a washer/dryer; 100% LED lighting with installed dimmers; an induction range; and previously mentioned features.

In addition to energy efficiency measures, Dwell also focuses heavily on making houses safe and healthy. All their houses use low- to no-VOC products and have no carpet installed, which allows for better indoor air quality. They also install HRVs that constantly supply the houses with fresh filtered air!

The builder set out to overcome these obstacles by planning ahead, communicating his plans to the HOA board as far in advance as possible. He also sent notice of his plans, indicating that if he did not hear back from the board by a certain date, he would take it as approval to move forward. This allowed him to keep a timely schedule.

Despite not being able to puncture the exterior walls to make energy-saving improvements, the builder was still able to reduce the unit’s overall energy consumption by over 30% compared to its reference home. A combination of indoor storm windows, a heat recovery ventilator (HRV), a heat pump water heater add-on, heat pump dryer, 100% Energy Star appliances, and 100% LED lighting allow for significant savings! WaterSense certified fixtures, a low-water-use dishwasher and clothes washer, and removing the existing garbage disposal also reduce water consumption, which ultimately save energy on water heating!

In addition to saving energy, the HRV significantly improves the indoor air quality. An HRV supplies outdoor fresh air while tempering cold air as it comes in. With a HEPA filter, this reduces pollutants carried in from outside—so valuable as wildfire events become more frequent in the Seattle area. The builder also selected interior finish products that are no- and low-VOC, Green Guard certified, and FloorScore certified, meeting stricter standards for indoor air quality.

Removing the carpet initially wasn’t allowed, due to sound requirements, so the builder took the time to educate the HOA board where he could. Armed with information, he demonstrated the sound qualities of carpet vs. cork flooring with cork underlayment and was able to convince the board to approve replacing the existing carpet with hard-surface cork flooring.

In contrast, the interior is bright and well-lit by daylight flooding in through the windows, which will help minimize energy usage for lighting during the day. The house is also extremely well insulated; the exterior walls are covered in three inches of rigid foam, in addition the fiberglass blown-in blanket systems (BIBS) on the interior. The ceiling has a minimum of six inches of rigid foam on the exterior and the 16-inch-deep trusses are also packed with fiberglass BIBS. AeroBarrier helps reduce overall envelope leakage.

By combining AeroBarrier with a well-insulated envelope, RW Anderson was able to decrease the heating loads so the whole house could be heated (or cooled) with just a few ductless mini-split heads. This project also utilized a high-efficiency gas tankless water heater, Energy Star appliances, and high-efficacy lighting, allowing them to save over 40% more energy compared to a code-built house.

Beyond energy efficiency, many of the interior design choices were selected not only for their aesthetics, but also for their sustainability. Rather than using new materials throughout, many of the doors, light fixtures, and other products are salvaged material, with old markings bringing charm and character. The oak flooring used through is FSC and FloorScore certified.

The combination of all these items and the use of long-lasting siding products will reduce the overall impact on the environment while creating a beautiful, durable house.