Pressure is mounting for the building and construction industry to become more sustainable. Designing more energy-efficient buildings is part of that, but reducing embodied carbon is a more pressing — and often challenging — issue.
Embodied carbon in buildings comes from many sources, but that also means there are many ways to reduce it. Here are eight of the best ways teams can prioritize embodied carbon reduction in their projects.
1. Consider Renovation Over New Construction
The type of project teams take on is one of the most influential factors in their building’s embodied carbon. Renovation and refurbishment are far more sustainable than new construction because they require less work and fewer materials. Instead of creating an entirely new set of embodied carbon emissions, teams will add to an existing one.
Renovation opportunities are more widely available than they may initially appear, too. More than one million homes in the U.S. replace their siding every year, so firms could sustain themselves on these lower-carbon projects. Even if they don’t constitute a company’s entire business model, focusing on them would significantly drop embodied carbon.
2. Use Recycled Materials
The materials a project uses are another critical component of reducing embodied carbon. Fossil fuel-powered equipment is responsible for a lot, but more than 50 percent of total project emissions come from just three materials — steel, concrete and aluminum. Thankfully, these materials are also relatively easy to recycle.
Recycling metals and concrete is not typically an emissions-free process, as it often involves fossil fuel-powered furnaces. However, these emissions are far lower than those that result from mining and producing virgin materials. As a result, opting for recycled resources instead of new ones produces significant overall improvements.
3. Design for Structural Efficiency
One easy-to-miss part of how to reduce embodied carbon in construction is to consider material efficiency in the design phase. Since materials account for so much of a project’s carbon footprint, teams should try to use less of them if possible. The best way to do that is to design structurally efficient buildings.
Curtain walls and metal panels offer more structural integrity in a smaller form factor than other building enclosure systems. Architects can also consider different framing methods to provide more strength with less material. Getting creative with these design choices can help ensure lower embodied emissions from the project’s beginning.
4. Capitalize on BIM Software
Building information modeling (BIM) platforms can help design these resource-efficient projects. Clash detection and similar features can highlight improvements and potential issues so teams can create the most efficient designs and avoid rework in the future.
BIM can also help prevent time workflow-related errors. These tools alert teams to issues like conflicting schedules or hazards like unnecessary heights — the leading cause of fatalities in construction. When teams recognize and adapt to these problems, they can finish projects sooner, leading to lower overall emissions during the construction phase.
5. Use Carbon-Sequestering Materials
Firms can also prioritize reducing embodied carbon by using carbon-sequestering materials. These are resources like wood and other plant products that naturally absorb and store carbon. Normally, plants release this carbon back into the atmosphere when they decay, but turning them into construction materials ensures they keep this carbon throughout the building’s lifecycle.
Wood is a carbon-storing material, but since trees take a long time to grow back, its environmental benefits are limited. Bamboo, straw and hemp grow faster, so they’re more renewable. Teams may be unable to use these materials in support structures, but they can provide carbon-sequestering insulation in building enclosures.
6. Use Low-GWP Insulation
Insulation traditionally carries a significant carbon footprint, making it ideal for disruption. Conventional spray foam has high global warming potential (GWP), largely thanks to its harmful blowing agents, but today’s market offers plenty of low-GWP insulation options. Water-blown spray foams and hydrofluoroolefins (HFOs) act similarly to conventional foam but with a lower GWP.
Some foams today are made of soybean oil, making them more renewable. Teams can also avoid spray foams altogether and opt for alternative insulation like wood fiber. These materials may come at a higher upfront cost, but their significant improvement in reducing embodied carbon is worth the expense.
7. Look for Low or Zero-Emissions Equipment
While materials are the biggest concern, reducing equipment-related emissions is another key part of reducing embodied carbon. Much of the machinery construction teams rely on uses diesel or gas engines, which produce considerable greenhouse gas emissions. Looking for electric and renewable alternatives instead can help minimize this impact.
Electric construction vehicles are less common than fossil fuel ones, but they’re still available. Several manufacturers are coming out with hydrogen or battery-electric models as sustainability becomes an increasingly important business model, so teams should look for these options. Construction crews can also use hydrogen-powered generators to provide zero-emissions electricity to electrical tools.
8. Emphasize Waste Reduction
Building firms should embrace a spirit of waste prevention. The U.S. generated twice as much construction and demolition debris as municipal solid waste in 2018 alone, representing a huge amount of embodied carbon that ultimately doesn’t serve a functional purpose. If teams can reduce the amount of waste they generate, they can make their projects far more carbon-efficient.
Many strategies can help reduce waste. Using BIM clash detection to prevent rework is one of the most helpful. Teams can also design building enclosures to use materials in common sizes to reduce the amount of trimming necessary. Similarly, designing for prefabrication will help make panels use less material while providing the same structural benefits.
Reducing Embodied Carbon Is Critical
Reducing embodied carbon in buildings is a complicated but possible process. It can be intimidating to think of how many disparate factors add to these emissions, but that variety has a positive side, too. It means building and construction firms have many paths to take to reduce their projects’ carbon footprints.
Each of these eight strategies can result in significant emissions reductions in the right circumstances. Implementing several of them will lead to the biggest possible improvements. As firms follow more of these steps, they’ll become industry standards, leading to carbon reductions across the entire sector.
