The importance of addressing both embodied and operational carbon in the building industry and how thoughtful design can help
An urgent call for decarbonization
In 2017, the United Nations Environment Program shed light on the building industry’s environmental impact in the World Global Status Report. Building and construction currently account for 39% of the world’s total CO2 emissions, a number which has been on an incline for the past ten years.
The building sector must begin incorporating energy-efficient practices into its workflow to decrease environmental impacts.
In the United States, regulations at a state level have been put into place to combat rising levels of carbon due to construction. The state of New York, for example, has declared the public goal of reducing carbon emissions by 80% by the year 2050. To achieve this, New York legislators enacted Local Law 97, what’s being referred to as “the most ambitious climate legislation for buildings enacted by any city in the world.”
California has also made a regulatory push towards decarbonization with the introduction of the Buy Clean California Act, which requires that maximum Global Warming Potential (GWP) rates be established and published for certain building materials that the state is purchasing.
Despite a legislative push toward more sustainable building practices and products, initiative is still needed from builders and designers at both an individual and company level. This means taking into account measures for decarbonization in new projects as well as addressing areas for improvement in existing buildings, especially in terms of renovations and replacement of materials.
Target structural systems
Structural systems contribute up to 80% of a building’s embodied carbon. Opting for sustainable alternatives when building these systems will reduce carbon emissions significantly. The material chosen for construction has a prominent role in our built environment. Each industry has manufacturers and products that are focused on lowering their embodied carbon. The Buy Clean California Act mandates that materials used must adhere to GWP limits set by DGS to decrease the environmental harm. Understanding the impact of each material through Environmental Product Declarations (EPDs) and/or Greenhouse Gases (GHG) impact tracking prior to specification will help you lower your projects’ embodied carbon emissions at each stage of production.
Addressing embodied carbon: a big picture approach
Many designers and builders are focusing on the construction of high-performance or net-zero-energy (NZE) buildings, which emit as little carbon as possible when in use. This is an important effort in reducing operational carbon. However, while these buildings focus on operational carbon, embodied carbon continues to grow. A crucial first step to holistically reducing carbon emissions is understanding the difference between embodied and operational carbon, and why addressing both is a must.
Embodied Carbon: The amount of carbon emitted during the making of a building. This includes extraction of raw materials, manufacture and refinement of materials, transport, the building phase of the product or structure, and the deconstruction and disposal of materials at the end of life.
Operational Carbon: The amount of carbon emitted during the operational or in-use phase of a building. This includes the use, management, and maintenance of a product or structure.
Operational carbon currently accounts for 28% of global GHG. Though embodied carbon only accounts for 11% now, with the estimated increase in construction, by the year 2050 embodied and operational carbon emission levels will be the same.
Addressing build-related embodied carbon emissions is an important part of reducing the building and construction industry’s carbon footprint.
The good news is that most projects can reduce their embodied carbon by 10-20% at no additional cost. Making a few simple adjustments and selecting the right products can help designers and builders significantly decrease levels of carbon emitted from their projects.
How to: methods for reducing embodied carbon
Design with efficiency in mind
The road to sustainable building starts long before the actual construction phase. It’s essential to account for carbon emissions through raw materials, waste and disposal, and the entire life cycle of materials. Designing with efficiency and sustainability in mind can greatly reduce a building’s carbon footprint.
Design for less material
The less material required for a project, the lower the environmental impact. This may result in a more efficient, compact building form, which can reduce a building’s total embodied carbon up to 5%. Modifying specifications for building elements (such as lightweight structural design) can result in up to a 20% decrease in embodied carbon.
Design for less waste
Waste reduction should be top of mind during the initial phases of a project. There must be collaboration between designers, suppliers, and contractors to specify procedures that minimize waste. For example, formless materials can help reduce waste from cutting/fitting formed materials. Suppliers can help minimize waste through elimination of unnecessary packaging and contractors can take measures to prevent damage, thus wasting less materials. Off-site and modular construction, when possible, greatly reduces waste and improves waste management.
Design for the long haul
Designers should be considering a material’s entire life-cycle cost: more durable products can help prolong life and decrease carbon emissions down the road. It is also crucial to design with deconstruction and reuse possibilities in mind. Materials should be able to disassemble and/or be reused to increase efficiency and decrease damaged materials and waste. Working with a material’s entire life cycle in mind and making it easier to reuse salvaged materials can significantly reduce a building’s embodied carbon footprint.
Use sustainable alternative materials
Not all projects require new materials. Opting for recycled or salvaged materials can reduce embodied carbon levels up to 10%. Using materials that contain recycled elements has the potential to reduce environmental impacts by taking carbon emissions during extraction of virgin materials out of the equation. That being said, it’s important to do your research. “Recycled” does not invariably mean more environmentally friendly. In some cases, the processing and take-back of recycled materials can be just as carbon intensive, so it’s important to understand the process that your materials will go through before they get to you.
Make a difference with sustainable design and products
Building professionals have a responsibility to optimize their processes in favor of decarbonization. Sustainability should be a leading factor in all building decisions being made, from design to product selection. Project planners and architects can easily opt for more sustainable alternatives by making note of embodied impacts detailed in the Environmental Product Declaration. Check out SPOT’s platform for an easy way to assess product characteristics and drive sustainability in your builds.
This article merely scratches the surface of the immense number of ways good practices in building can impact carbon emissions. Whatever your role in the building process, a thoughtful approach to your craft can make a huge difference in the long run, and benefit your business, customers, and the planet.