This house was designed by First Lamp to look like alternating stacked blocks, which creates extensive overhangs. In addition to the overhangs, First Lamp added a large cantilevered roof allowing for the main entry, porch, carport, and deck to be covered while providing lots of usable space to spend time outdoors year-round. To create additional privacy for the porch area, an outdoor concrete wall was built to provide a separation between the street and living space.

The home’s uniquely designed interior highlights Shou Sugi Ban paneling surrounding the fireplace, recycled cardboard light fixtures, and a small indoor atrium. Other interior finishes include polished concrete on the main floor, bamboo flooring on the additional levels, fiberglass-clad wood-framed windows, locally-made cabinets, and recycled-content quartz countertops.

On top of the design features, this house is also built to be energy efficient. Rigid sub-slab insulation and blown-in fiberglass in the walls and roof provide a good thermal envelope, while the hybrid heat pump water heater designed for domestic water use, radiant slab, ducted and ductless mini-splits, Energy Star appliances, and LED lighting all help to keep bills small. And for fresh air, the HRV will do the trick!

Built Green Highlights

Site and Water

• Native vegetation and trees saved with extensive protection during construction
• Topsoil stockpiled and covered on-site for reuse
• 100 percent pervious hardscaping with bioplanters for maximum water infiltration
• Vegetated roof surrounding the deck on the second level
• No grass on-site; all drought-tolerant landscaping

Energy Efficiency

• 1.96ACH @ 50Pa blower door score achieved with an Intello Plus interior and a Solitex Mento exterior air and vapor barrier combination
• Passive solar strategies incorporated into the house design
• Hydronic slab, ductless, and ducted mini-splits for efficient space heating
• Hybrid heat pump water heater and Lifebreath HRV installed
• Electric vehicle car charger integrated into the carport

Long before they broke ground, Green Canopy Homes devised a plan for how to build a healthy, energy-efficient, and beautiful home. They worked with their subcontractors and verifier to ensure energy use would be offset with solar panels, the home would be airtight, and the finishes would promote good indoor air quality.

The project boasts 13.3 kW of solar panels to offset the energy use in the all-electric house. Both ducted and ductless mini-splits are used to heat and cool the home. Domestic hot water is provided by a hybrid heat pump water heater, which functions similarly to the ducted/ductless mini-split system, moving heat from the air to heat water at an efficiency of over 300%. In addition, LED lighting and ENERGY STAR appliances were installed to reduce the electrical load.

To maximize the efficiencies of the systems installed, the home was air sealed to a blower door score of 1.0 ACH @ 50Pa and insulated to R-23 in the exterior walls and R-72 at the ceiling. With such a tight building envelope, a balanced ventilation system was needed to provide fresh air throughout the house. The heat recovery ventilator allows for the heat from stale exhaust air to be transferred to incoming air, minimizing the overall energy needed to heat air being supplied to living spaces.

In tandem with the airtightness and balanced ventilation, the project promotes excellent indoor air quality in its material selection. The bamboo, linoleum, and cork flooring installed are naturally-made and third-party certified for indoor air quality (GreenGuard and Floor Score for the cork and linoleum, respectively). The combination of materials and paints, caulks, and adhesives with little to no VOCs minimizes off-gassing within the home.

Congratulations to Green Canopy for their first net zero energy project!

Built Green Highlights

Site and Water

• Drought-tolerant plantings
• 100 percent permeable hardscaping
• Low-flow plumbing fixtures

Energy Efficiency

• Ducted and ductless mini-splits
• Hybrid heat pump water heater
• Blower door score: 1.0ACH @ 50Pa
• ENERGY STAR appliances
• 13.3 kW of solar panels

Just north of the entrance to Seward Park, directly across from the water’s edge resides The Lake House. Built in 1919, the historical home was designed by renowned California-raised architect, Edwin Ivey, in the Spanish Eclectic style reminiscent of the homes found in Pasadena. A street-to-street lot, prime location, and a magical facade sparked the interest of the founders of Dwell Development (Dwell), Abbey and Anthony Maschmedt. For them, it was love at first sight. Their challenge was taking the sustainability practices they employ in new homes and implementing them in a home over a century old. It was a challenge they fully embraced when they devised their plan for The Lake House 2.0.

Dwell set out to do something extraordinary with this amazing parcel located on Lake Washington Boulevard South. Their job was to solve the puzzle of taking advantage of a unique development opportunity while maintaining the original integrity of the existing home—with a little over 20,000 square feet there were endless possibilities.

Fortunately, the existing home sat on the front portion of the lot with a massive grass front yard facing the lake. Behind the house, there was an existing carriage garage, that was originally intended for a vehicle and a caretaker. Beyond the garage was a large, landscaped yard that fronted 57th Avenue South. The site being street to street, provided room for development and design.

In most cases, similarly zoned sites would see the existing house demolished, then subdivided to create 3 new approximately 7,000-square-foot parcels, with 3 new single-family homes built. However, the Lake House was architecturally significant, and while it would take a lot of work to modernize it for another century of use, the Maschmedts knew that preservation had to be the goal. Then again part of modernization is also using resources more wisely, and land and housing are finite resources. So they had to also re-envision the site to maximize such valuable resources. Ultimately, they decided to preserve the Lake House with a new DADU and office, then subdividing it into two parcels to build a new single family home with an accessory dwelling unit. This increased the housing capacity of the site to 4 housing units.

Curve balls are expected when planning a project like this, but the Covid-19 pandemic presented unique challenges when it came to design decisions. During the pandemic Seattle Parks, which owns Lake Washington Boulevard, had decided to shut down the boulevard regularly to accommodate pedestrians, bikes, and strollers. Continual access from the back of the Lake House needed to be maintained, because there was a looming threat of a permanent shutdown of the boulevard to cars.

The biggest obstacle of the project would be updating the existing single-family home. Though Dwell is well-versed in sustainable new construction, historical restoration was not on their resume yet. They needed to balance preserving the amazing home, saving it from the landfill and maintaining its original charm and character, while updating and modernizing it to assure it met all the expected energy efficiency of a Dwell Development home. Ultimately, the goal was for The Lake House 2.0 to be Dwell’s first Net Zero Energy renovation.

Inclusive of the down-to-the-studs renovation of the existing home, the existing carriage garage was demolished and replaced with their first Net Zero Energy DADU. The DADU includes a 2-car garage that is accessed off of 57th Avenue South and serves as the new Dwell Development office headquarters. In addition, another first for Dwell, a Net Zero Energy Ready 5-Star Built Green single-family home with a legal AADU was built on the remaining portion of the parcel in the rear overlooking the main house and the lake.

Dwell applied all their standard, tried and true, sustainable systems and practices to the project. The existing house was stripped down to the studs, and a 1,500 sq ft addition was added to the back. Originally built with no insulation, they knew that proper insulation would be critical. After removing all the plaster and lathe, they added blown-in cellulose insulation. The exterior was also clad in a rain-screen Portland Cement Stucco, a cladding very unusual for the Northwest. The new stucco on the addition would need to match perfectly to blend old and new. No stone was left unturned in preservation. Existing millwork, windows, light fixtures, and doors were removed, stored, and eventually returned to their rooms. Their goal was to avoid waste and reuse as much of it as possible.

Heating and cooling and air quality are essential to a sustainable home. Anthony and Abbey called on trusted manufacturers, because they knew they couldn’t do it all alone. Partnerships were essential to the project. Mitsubishi and Panasonic lent Dwell their HVAC and fresh air consultants to design a new type of state-of-the-art heating/cooling and fresh air system. They also donated all the equipment towards this never-used-before system. The HVAC system features an ERV integrated into the ducted heat pump air handler to provide triple filtration and air scrubbing, maintaining premium fresh air and thermal comfort throughout the home.

The Lake House and its DADU is designed for a 16kW solar PV array that provides it a net positive energy balance. The solar PV will not only power the home and DADU, but also the swimming pool and an electric vehicle. The single family home is solar PV ready and includes two level II charging outlets for EVs.

The final results are something Dwell Development is very proud of. A feather in their cap and a homage to sustainability. Having completed a 5-Star Net Zero Energy Certified Built Green renovation, a 5-Star Net Zero Energy Certified Built DADU, and a 5-Star Built Green Net Zero Energy Ready Single-Family Residence with AADU simultaneously in one project, Anthony and Abbey Maschmedt of Dwell Development believe anything is possible when you set your mind to it. Lake House 2.0 is ready to roll into the next one hundred years.