MATERIALS

About The Petal

The intent of the Materials Petal is to help create a materials economy that is non-toxic, ecologically restorative, and transparent. Throughout their life cycle, building materials are responsible for many adverse environmental issues, including personal illness, habitat and species loss, pollution, and resource depletion. The Imperatives in this section aim to remove the worst known offending materials and practices and to drive business toward a truly responsible materials economy. When impacts can be reduced but not eliminated, there is an obligation not only to offset the damaging consequences associated with the construction process, but also to strive for corrections in the industry itself. Over the past decade, the Red List has transformed the building industry from one where ingredients were held in secret to one where transparency is becoming the new normal.

When choosing materials we considered 4 basic aspects:

Toxicity of ingredients
End of life options
Carbon footprint
Sustainability / Renewability
Performance
Where was it made

Net Positive Waste

Our house was solidly built in 1986 but deteriorated over time due to a lack of maintenance. It needed major renovations when we purchased it in 2020. Windows, doors, siding, roof and deck are being replaced. We will remodel bathrooms and kitchen and we will replace the existing vinyl floor with tile and hardwood floors.

We have disassembled the redwood deck and have used the wood to build a mailbox post and a child's sandbox. We are planning to use more of the reclaimed decking to build raised garden beds, working toward net positive waste as we also increase our home food production in keeping with the Place Petal.

Toxin-free Materials

The two materials making up the bulk of the renovation project will be triple-pane windows by Cascadia and metal siding and roofing from AEP Span. Both products are toxin-free and can be found on the Living Building Challenge's Declare database, a product directory for healthy building materials.

One example of a common toxic ingredient found in stainless steel and steel coatings is Hexavalent Chromium. In addition to ensuring that our siding and roofing are free of this cancer-causing element, we also chose a toxin-free low flush toilet and designed the construction of our woodstove's steel heat shield to be toxin-free.

Unpainted wood removed during demolition that cannot be reused due to damage or decay as well as scrap wood cut from new lumber and remnants of our wood fiber external insulation will be buried in hills, swales and other built land features designed to slow, spread and sink rainwater on site, in keeping with the Water Petal.

We replaced fibreglass insulation throughout the house with new batts made from 100% sheep wool manufactured in Nevada. Though they are more expensive than fibreglass, they have a slightly higher R-value, a lower carbon footprint and they are compostable at the end of their useful life (photo below left). To achieve Passive House, we needed to reduce thermal bridging by adding a continuous external layer of insulation to the house. We chose to use compressed wood fibre insulation manufactured in Germany (photo below right) instead of closed cell spray foam which exposes workers and occupants to toxic ingredients.

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Sourcing Locally

The Standard requires that we source a minimum percentage of our building materials (by cost) from within a certain distance of our project location. We are required to source a minimum of 20% from within 500 km, 50% within 1,000 km, and at least 75% within 5,000 km.

All Metal Sales' final assembly location is only 140 km away from the project site. This is why we are able to source approximately 50% of our material budget from within 500 km. However, Cascadia windows will make up 40% of our budget but the final assembly location is more than 1,000 km from us so we would not meet the second sourcing requirement.

We will get an exception to use Cascadia windows due to the overall savings on the home's carbon footprint. The Cascadia Passive House-certified windows and doors will allow us to reach Passive House standard. A Passive House uses substantially less energy for heating and cooling. Since solar photovoltaic panels come with a carbon footprint too, we can lower our net carbon footprint by reducing the number of solar panels we need, since we will use less energy for heating and cooling.

Sourcing Sustainably

At least 80% of the wood used in construction must be Forest Stewardship Council (FSC) certified or salvaged.