Energy codes have done a good job of moving California architecture to more energy efficient buildings. However, green building needs to also include green building materials.
Back in the 1990s a great deal of attention in the green architecture community was placed on materials. Materials were researched and compared for their toxicity, life cycle impacts on the environment and human health, carbon footprint, sustainable yield, cultural impacts of extraction and more. However, as concern about the climate has grown and disagreements sprang up on the ‘greenness’ of various building systems and materials, the focus has generally shifted to energy efficiency and more recently shifting to 100% renewables.
While CALGreen has incorporated standards to limit off gassing of some toxic chemicals, there are many human and environmental health issues of materials these standards don’t address. Here are some excellent resources to fill the gaps:
- Healthy Building Network’s HomeFree offers a short, easy to use specification focused on indoor air quality and health. Healthy Building Network also has extensive database on chemical content and environmental impacts for thousands of products and great articles explaining their research. https://homefree.healthybuilding.net/reports
- The Living Building Challenge, a third party green building rating system similar to LEED, has a comprehensive Red List of chemicals to avoid and a database with materials meeting those standards. https://living-future.org/declare/declare-about/#the-red-list
- The Green Science Policy Institute provides guidance on avoiding toxics in the home. They also have a series of short videos breaking down the toxic chemical landscape into 6 classes, allowing the layperson to understand the general problems. http://greensciencepolicy.org/
- The Forest Stewardship Council provides the most comprehensive third party certification for sustainably harvested wood.
What we build with also has a significant impact on the climate. The embodied energy or the carbon footprint of building materials varies widely. Using low carbon materials for construction is critical in addressing climate change because the greenhouse gas emissions savings are accrued earlier, at the time of construction, when they have the biggest impact. Prioritizing low carbon materials can significantly reduce the lifetime carbon footprint, and in some cases even reverse it!
Metal and plastics in general have a very high carbon footprint. Concrete, while lower in embodied energy per pound, is used in such great quantities that its global warming impact tends to dwarf that of other materials used in construction. Blowing agents used in some of the foam plastic insulations have such high carbon footprints that their addition to a building can negate the operating energy savings for decades. For more information, The New Carbon Architecture by Bruce King offers inspiring examples and details of low carbon construction. https://ecobuildnetwork.org/projects/new-carbon-architecture
If the health of workers, occupants and our planet are not reason enough to use healthy building materials, fire is yet another one. The toxicity of building materials and furnishings can be amplified when they are burned. Smoke that engulfed the North Bay – and blanketed the entire Bay Area – was laced with dangerous chemicals: dioxins, furans, hydrogen cyanide and heavy metals, threatening the health of all. Sadly, firefighters are known to have some of the highest rates of cancer. Frequent exposure to these kinds of chemicals may be a contributing factor. Many of these dangerous chemicals are also left behind in the ash.