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

The project further optimizes resources by utilizing Energy Star appliances, a common laundry facility, low-flow water fixtures, high-efficiency domestic hot water system, and effective unit ventilation. Other interesting features include an outdoor common space tucked behind the building for some respite from the hustle and bustle, no carpet in units, specified low-emitting building materials, and a secure bike room.

The health and transportation-oriented features of Maude extend beyond the property line through proximity to community services and a transportation options portal in the front lobby. Utilizing the “Transit Screen” service, the lobby is a transportation information hub, providing status on bus, light rail, share car, traffic, and weather. This is fitting for this active area near daily needs and with access to a King County Metro bus hub, I-5, and the soon-to-be-open Roosevelt Station, servicing Sound Transit light rail, all within one to two blocks of Maude.

Built Green Highlights

Site and Water

• Infiltration system for rooftop runoff
• Nontoxic outdoor material used for landscaping
• No turf grass
• Low-flow lavatory, showerheads, and kitchen fixtures
• Recirculation pump hot water systems
• Centralized compost collection facility on ground floor
• Transit-oriented development
• Replaced impervious surfaces with pervious surfaces: green roof, vegetated wall, and permeable pavers
• Conducted training sessions for maintenance staff

Energy Efficiency

• Ultra-high efficiency central water heating with 95% thermal efficiency
• Energy Star appliances and exhaust fans in units
• Water-saving and energy-efficient washers in common laundry facilities

Guest post by Aaron Barnett, Cascade Built’s Comfort Systems division

One way to meet Built Green standards that provide client satisfaction as well as builder advantages is the use of cutting-edge mechanical systems. Heat recovery ventilators (HRV) supply continuous fresh air to the living spaces of a home and control humidity. Heat pumps provide highly efficient space heating and cooling without introducing combustion products into the home. Heat pump water heaters can offer excellent efficiency and greater hot water availability than other systems. However, realizing these benefits requires that these systems are designed and implemented correctly. The post will dive into the benefits of these systems, how they can help a project achieve Built Green certification, and how to plan and install them correctly.

Heat pump systems are rapidly growing in popularity due to their efficiency and their ability to deliver both heating and cooling in one package. As summer temperatures rise in the Northwest, the demand from clients for cooling has risen as well. Heat pumps are much more efficient than current furnace and resistance systems due to the fact that they harvest energy from the ambient air outside the building. Heat pumps come in a variety of configurations and sizes and the systems can be scaled to serve loads ranging from small apartments to large commercial and multifamily applications. Correct design is key for these systems and Built Green encourages the use of Manual D and Manual J calculations in the design process, which will dramatically improve the efficiency, comfort, and durability of the home. Built Green also awards significant points for using ductless heat pumps, and additional points for using high quality ones that include features such as the ENERGY STAR label, ECM motors, and zonal controls—features which are commonly available on reputable equipment. 

Heat recovery ventilators complement any high-quality build, providing better energy efficiency and radically improved indoor air quality. An HRV runs continuously, bringing in fresh air from outside and exhausting stale air from inside. It uses a heat exchanger to conserve the energy that has been put into conditioning the air inside the home and filters all the air that passes through it, so allergens, dust, and other common pollutants are significantly reduced. HRVs provide benefits for all homes and Built Green offers five points for the installation of an HRV on its single-family/townhome checklist, but an HRV also becomes necessary for the proper functioning of a building built to comply with some of the more stringent Built Green envelope requirements. Indeed, installing an HRV is actually a requirement for Built Green’s highest certification level, Emerald Star.