Building Lasting Roots
Buildings account for two-fifths of greenhouse gas (GHG) emissions, with concrete and steel each responsible for ~7% of global GHG emissions every year.
Our region has a one in ten chance in the next fifty years of facing an earthquake of greater magnitude than Japan’s 9.1Mw earthquake/tsunami from 2011, but an eighty percent chance of a 6.5+ megathrust earthquake occurring over the same period.
To cope with these crises, we must build our homes with quality materials.
CLT: Cross Laminated Timber or CLT is an important alternative to steel and concrete which are each responsible for 8% of total GHGe. By gluing planks together in jenga-like fashion, architects have created a super strong, rigid but flexible, highly flame and heat resistant, (generally) renewable, and naturally carbon negative framing material.
Low Carbon Concrete:
Concrete has long been the standard for building large-scale projects. Despite real benefits it’s unfortunately contributing to a global sand crisis and the climate crisis.
During the process of making cement—which is the “glue” that holds together concrete—large amounts of CO2 are released from industrial kilns. This is why the cement industry is responsible for 7% of global GHGe. For example, AshGrove cement plant is Seattle’s largest GHG polluter. But engineers are now able to encase CO2 as a mineral inside concrete, helping to keep carbon out of the atmosphere. In Seattle, efforts have just begun recently to make the critical step towards carbon negative concrete.
What to Leave Out: With the health and safety of occupants and the planet as a priority concern its important to consider commonly used hazardous materials in our homes. Seattle-based sustainable design firm Miller Hull has developed a “red list” of materials it has decided not to use in construction. Items include PVC which offgasses cancer-causing dioxins during production, and flame retardants which can cause infertility.
Reclaimed Wood Flooring: Our designs utilize environmentally friendly recycled wood flooring. While keeping valuable resources out of landfills, we also give residents the lush and timeless feel of real wood, rather than laminate (the more popular choice in affordable housing). This choice works in tandem with Seattle’s mandatory salvage assessments, and reduces waste created by construction and demolition.
Walls: Insulation is a vital component to making an “envelope” which retains temperature, dampens sound, and protects the interior. Insulation materials like hemp, icynene (castor oil) recycled denim and cellulose (made from newspaper) help reduce the environmental footprint to 1/10th of traditional pink fiberglass and other plastic foams. “R ratio” is the number for insulation’s resistance, a reasonable minimum is 5:10:20:40:60 or windows at R-5, subslab at R-10, basement wall or slab perimeter at R-20, walls at R-40, and ceiling or roof at R-60. Formaldehyde-free fiberboards and OSB plywoods help to frame double stud walls with engineered lumber techniques utilized in PassivHaus Design.
Windows: When insulating a home, windows are generally the “weak spot” with R-values ( a metric for insulating capacity) much lower than the surrounding wall. High-efficiency windows have features to address this such as 2+ panes of glass with low-emissivity (low-e) coatings on the glass panes and a nontoxic inert gas in between.
Energy STAR Appliances:
The little blue “Energy STAR” logo appears on a appliances which meet a basic standard of energy efficiency that exceeds federal minimums.
However, taking on the EPA’s “Only the best will do” motto means drawing exclusively from the ENERGY STAR Most Efficient 2022 list. Consumers can browse that list online to find products meeting the highest standards.
Heat Pumps: Heat pumps replace the need for heaters and air conditioners. Instead of generating cold or hot air, air heat pumps work by moving hot air to outdoors during cooling mode and extracting heat from outside air to pull inside during the winter. This works especially well in Seattle. By switching to electric heat pumps, buildings slash up to 70% of their emissions, and it could cut out 1/10 of the nations GHG footprint! Ground source heat pumps (GSHPs) are even more efficient, (even for large apartment buildings), if the ground is well suited and stable.
Pipes: The piping industry lacks standout candidates. However, PEX (crosslinked Polyethylene) has the benefit of lasting up to 100 years, good insulating qualities, ease of installation, and that it doesn’t corrode. Until a more viable piping solution is innovated, PEX plastic piping is the best alternative to copper or other plastics.