Plumbing Air Admittance Valves at FutureFit Home

We reduced air leakage and thermal bridges by replacing our through-roof plumbing waste piping vent system with a combination of air admittance valves (AAV) and a two-way, filtered outdoor valve. Oregon’s plumbing code recognized AAVs, but restricted their use to 3 per house and required one through-roof vent. On appeal, the City of Portland allowed us to install AAVs according to manufacturer’s guidelines so we could eliminate all through-roof vents, using the “alternate materials and methods” provision through its Alternative Technology Advisory Committee (ATAC) process.

CO2 Heat Pump Water Heater in Madrona Passive House

Seattle’s residential building code requires domestic hot water heating system be tested and listed by a testing agency approved by the State of Washington. in the 1990s, Japanese engineers developed heat pump domestic hot water heaters using CO2, an abundant, natural refrigerant. These systems are known as “Eco-Cute” which means environmentally-friendly hot water because using CO2 avoids conventional synthetic refrigerants which have high global warming potential (GWP). Although Sanden’s Eco-Cute is not yet tested by an approved agency, the City of Seattle’s Innovative Technology Advisory Committee (ITAC) recommends Hammer & Hand be permitted to install the CO2 system as an alternate material because of its superior performance and environmental attributes if it meets four conditions.

“Off Grid” Net Zero Water at Birch Case Study House

This groundbreaking project is the vision of innovative designer Dan Welch of [bundle] design studio in Bellingham, Washington. Welch designed and built his own home as a case study to validate principles of the Living Building Challenge (LBC), and achieve an “off-grid” Net-Zero Water home. He and his family now use purified rainwater for all uses and treat all their wastewater on-site, approved through progressive local & state green building codes that allowed him to legally decline City water/sewer hookups.

State-approved vs. Site-built Composting Toilet in Birch House

To design and build his home to meet the Net-Zero Water imperative of the Living Building Challenge, architectural designer Dan Welch installed waterless composting toilets in his family’s home, and recycles their biosolids on-site “for beneficial purposes” in a manner approved by Whatcom County Health Dept. and City of Bellingham under State of Washington rules. Although he argued those rules prefer a two-stage “batch composter” for improved sanitation, the County health official required him to choose a continuous composter from the State approved list, rather than his own site-built design.

Undersized heating system at North Passive House

Because of a super-insulated, high performance “Passive House” design, a central heating system was not required to meet heat load requirements. The building official allowed a smaller-than-standard heading system, a Navien combi-heater: a high efficiency, tankless, natural gas powered water heater that delivers heated hydronic fluid to a fluid-to-air heat exchanger installed in ductwork for the home’s ventilation system. Energy efficiency, building science and technology make a house that is extremely airtight and insulated.

Undersized Heating System with DHP & HRV at Far Reach Home

This home’s exterior envelope was constructed entirely from SIPs, and the interior was heated with a Ductless Heat Pump and included a Heat Recovery Ventilator for indoor air quality, all resulting in an extremely airtight, energy efficient non-standard home. While no building codes were ignored, the home incorporates several systems many building officials may be unfamiliar with.

Kitchen Exhaust Ventilation with HRV at Ankeny Row

Green Hammer’s Ankeny Row homes meet the Passive House Standard with whole-house, balanced, continuous ventilation with heat recovery. This ventilation system includes an exhaust vent located in the kitchen. Code requires a direct-through-envelope, intermittent operation, high-volume range hood exhaust system. On appeal, Green Hammer demonstrated the passive house ventilation system is environmentally superior because it provides more ventilation than the code requires as well as heat recovery for greater energy efficiency. The City of Portland allowed this ventilation system as “an alternate method/material.”

Sanden CO2 Refrigerant Heat Pump Water Heater at FutureFit Home

Residential heat pump domestic water heating systems (HPDWH) use synthetic refrigerants with high global warming potential (GWP). In the 1990s, Japanese engineers developed an alternative HPDWH technology known as “Eco-Cute” that uses CO2 for refrigerant, a naturally occurring gas with global warming potential (GWP) 2,000 times less than synthetic. Oregon’s plumbing code requires hot water heating systems to be tested and listed by an approved agency (such as Underwriters Laboratories UL). Although it is not yet UL listed, the City of Portland allowed us to install the CO2 HPDHW system as an alternate material through its Alternative Technology Advisory Committee process.

Highest-Efficiency HRV without UL Listing for Futurefit Home

To futurefit our home (remodel for the future) to the Passive House Standard, we air sealed to reduce air leakage by a factor of 5. Without this “accidental ventilation” we needed to add balanced, mechanical ventilation with heat recovery. At the time, no UL-listed heat recovery ventilator (HRV) was available with the necessary combination of 75%+ effective heat transfer and low electrical consumption. The ZehnderAmerica CA 350 HRV was certified by the Passivhaus Institut (PHI) for superior performance, but it was not tested and listed by Underwriter’s Laboratory (UL). The City of Portland allowed us to install it without UL listing as an alternate material through its Alternative Technology Advisory Committee (ATAC) process. We enjoy superior ventilation, indoor air quality, and energy efficiency with our HRV.

Positive Impact Development at Clearwater Commons

A decade before the Washington State Dept. of Ecology made low-impact development (LID) the “preferred and commonly used method” for on-site stormwater management, Clearwater Commons LLC took advantage of a voluntary LID compliance path pioneered by Snohomish County from 2000 – 2005. In 2006, this tight-knit group of families embarked on a 6-year journey to design and permit their intentionally eco-friendly neighborhood, located on an ecologically sensitive site with wetlands and North Creek a salmon-bearing stream, using multiple techniques in combination for a net-positive result.