Sustainability is the hot word in ecologically-sensitive circles these days. But what does it really mean in architecture? Since sustainability has become a buzzword, it is now commonly used to indicate anything with an intent to be more ecological than the business-as-usual alternative. We prefer a more literal reading: a building is sustainable if its existence contributes to ecological well-being–it sustains life–not just that it’s less harmful.
Yet buildings, beyond their operational impacts, participate in complex systems such as material extraction, transportation, power distribution, and water treatment, so sustainability (relative to impacts from these systems) is extremely hard to measure, and therefore hard to objectively claim. The environment, like the body, is resilient and can withstand some shock and toxicity; but too much over a long period can be detrimental, leading to decline and even collapse.
Clearly buildings need to minimize negative impacts and maximize benefits. Loosely ranked, the most important impact categories are:
- Operational energy and emissions: since energy consumption has been the primary driver of climate change, this is top of the list. Buildings should make nearly as much energy as they consume over the course of a year, and they should not create emissions from burning fossil fuels. The Phius metrics offer a climate-specific target for all building types and locations.
- Embodied carbon: buildings should be made from low-carbon materials (plant-based and local), minimizing concrete, steel, and glass, maximizing salvaged products and buildings. While there isn’t a metric per building type yet, tools like BEAM can indicate general ranges, and buildings should be in the “Good” to “Great” range at least.
- Water use: buildings should ideally be water-net-positive as defined in the Living Building Challenge, using little and participating in a healthy hydrology. At least, commercial and institutional buildings should benchmark and fall low on the EPA’s ranking; and homes should meet Water Sense criteria, aligning with LEED’s requirements.
- Indoor air quality: interiors need to be healthy, or we’re poisoning people with buildings, which sadly is an all-too-common situation today. VOCs, toxic emissions from gas cooking and heating, and endocrine disruptors are just a few culprits that need to be eliminated. The Greenguard standard is a baseline for materials, the Declare label is the gold standard.
- Beauty: while less measurable than the other categories above, if buildings aren’t loved, they will not be kept, and that will lead to more waste. Beauty is another way of saying well-designed, which goes beyond visual appeal to mean fitness to function and context as well.
Principles of Sustainable Architecture
As we have pursued eco-friendly design over the past 20 years at TBDA, we have worked to clarify an appropriate design process and evaluation. As a result, we have identified three pillars that support our pursuit of sustainability: Energy, Materials, and Biophilic Design, and we use these to evaluate our work.
- Energy: this includes both operational and embodied carbon. We use the Phius metrics to establish the operational performance of the building, ensuring that the building can achieve annual zero operational energy with on-site or local energy production. By using these metrics and the principles of Passive Building, including energy recovery ventilation, we ensure that the building’s inherent design aligns with resilience, indoor air quality, and minimal mechanical demands while maintaining comfort.
- Materials: this encapsulates both embodied carbon and health. For embodied carbon, we keep below a maximum of 7kgCO2e/sq.ft. (for residences) to allow the embodied carbon spend to be offset by the carbon sequestration of healthy biomes (prairie, forest, etc.). For health, we ensure that all products are Greenguard certified at a minimum, while maximizing the use of Declare label products. This means no formaldehyde, no off-gassing vinyl, no toxic paints, sealants, and caulks, and no forever chemicals. The good news is that these choices often result in more natural materials, which people love!
- Biophilic Design: this is the art of designing for psychological well-being, by drawing on our innate connection to Nature. As outlined in another of our blog posts, biophilic design has been scientifically shown to benefit health, as seems intuitively obvious. But putting it into practice is more of an art than a science, as it takes sensitivity to client, site, and the creative process. When done right, the resulting environment brings a sense of peace and positive energy, a welcoming sense of place.
The Importance of Sustainable Architecture
Given that we are now a predominantly urban society, and that we spend typically over 90% of our time indoors, the performance of the built environment is paramount to our ability to survive and thrive. Only a few hundred years ago, with the population a tenth of what it is now and the majority of the population rural, our impact on the environment was much smaller. We didn’t give enough credence to the way we got into the habit of using toxic materials and processes. Now, with our giant industrial presence, we can look at sustainability as a binary proposition: we either build sustainably, or we decline. We either create a healthy ecosystem, or we will put ourselves on the endangered species list.
Architecture by itself can’t be purely sustainable–it needs to be part of a web of sustainable human systems in harmony with the earth’s ecosystems. So, in our time, sustainable architecture must aim to support such a system, and architects must help create that vision, along with urban planners, scientists, and artists.
Examples of Sustainable Architecture: elements and influences
One thing that sustainability is NOT is a look or a style. Ecological work must be part of its ecosystem, so it varies by place, by biome, by culture. The greatest sources of inspiration come from natural organisms and from early vernacular builders, who could only build from the resources at hand.
While we’ve depleted many of our original local resources, we have surrounded ourselves with other resources, including existing buildings. Some of our lowest embodied carbon projects are retrofits, in which we turned old buildings into new Passive buildings, keeping most of the original structure. In our new buildings, we specify carbon-sequestering insulation systems such as straw and cellulose to create highly insulated, carbon-negative thermal envelopes.
Another thing sustainable architecture is NOT, especially in a cold climate, is a concrete, steel, and glass building. Or even a very glassy building. Architects fell in love with glass boxes in the 1950s and beyond, as we started ignoring vernacular forms (inherently more passive) and started using tons more energy to heat and cool these flimsy things. Additionally, glass is very energy intensive to make, a double whammy. We aim to use glass mindfully, creating great natural light and views while maintaining adequate overall insulation levels; this becomes part of the biophilic strategy as well.
There are some great places to look for contemporary inspiration: ILFI’s Steven Kellert Biophilic Design Awards, and AIA’s COTE Top Ten awards. These programs recognize projects that are on the front edge of sustainable architecture.
If you’d like to start a sustainable architecture project, please contact us today.