Designing Net Zero Carbon Buildings

Design and deliver net zero carbon projects – and prove the results with One Click LCA.
 

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What is Net Zero Carbon?

Simply put, Net Zero Carbon means overall not speeding up the global warming. In details, it means that a project’s life-cycle greenhouse gas emissions from all sources sum up to zero, or less. These sources include:
  • Life-cycle impacts of operational energy and water
  • Life-cycle impacts of construction, including materials extraction, manufacturing, transport to the site, installation and wastage, repair, replacement, refurbishment and end of life processing
  • Benefits (avoided impacts from) energy exported from the project to other users
  • Benefits (avoided impacts from) reuse of materials after the project is decommissioned
  • Benefit from permanently sequestered carbon (if any)
That’s it.

Why Net Zero Carbon matters?

Commercially speaking, net zero carbon matters because leading construction clients and cities ask for it. You do not have to believe in global warming, or that it is important, to respond to market demands. World Green Building Council’s Advancing Net Zero Commitment has a range of signatories from entire nations to cities to leading long-term property investors. Even more investors who do not go all the way to net zero are interested in applying some of the best practices to maintain their credentials as responsible organisations. Why Net Zero matters in particular for the construction industry is simple – it’s because buildings and construction account for some 40 % of global greenhouse gas emissions.  

Impact of Decarbonisation of Energy Grids

Since fossil fuels were discovered, operational energy has been dominant source of life-cycle carbon emissions. Now energy policy has changed the game. For a building whose lifetime is half a century or more, energy grid decarbonization makes materials life-cycle impacts the dominant source of life-cycle emissions. The flip side of this is that if you expect to achieve your net zero carbon project by exporting energy, you have to export enough of it to offset your emissions before your grid to which you export has reached zero remissions to be able to balance your emissions out. Exporting zero-carbon energy to a zero-carbon grid won’t offset any emissions, right? This makes the materials carbon even more critical, as offsetting them by exported energy is getting harder.  

7 Design Strategies to Achieving Net Zero Carbon

First, reduce emissions from your project as far as practicable by
  • Reducing virgin materials demand
  • Reducing fossil energy demand
  • Reducing need for material replacements during building life-cycle
Then, restore climate balance to achieve net zero carbon by
  • Repurposing existing buildings and materials
  • Making your own materials and buildings repurposeable
  • Replacing fossil energy elsewhere
  • Sequestering (biogenic) carbon
Some climate benefits also arise from general end of life use of materials and in case of cementious materials, from their carbonization during and after the building life-time.

Accounting Net Zero Carbon with One Click LCA

Carbon accounting practices for construction works are largely set by EN 15804 and ISO 21930, which are the globally applicable standards for life-cycle assessment of construction works. One Click LCA is certified for compliance with both. One Click LCA has a range of tools that support Net Zero Carbon Design. The tools offer the full panoply of Net Zero Carbon Design capabilities, such as Global Carbon Tool, LCA for BREEAM UK, and LCA for BREEAM International. Tools’ scopes are set by the standards and certifications – for example, as LEED LCA does not include operational energy, so this also excludes possibility of having net zero approach including energy. With One Click LCA, you can:
  • Select from substantial range of reused and recycled materials to use in your carbon footprinting / LCA
  • Model preservation of existing building elements
  • Adjust material service life and wastage assumptions
  • Adjust end of life scenarios from the market standard practice e.g. to model product reuse (within boundaries of standards) is coming in the fall 2019
  • Export energy from the building to offset other energy flows at system level
  • Sequestrate biogenic carbon (for any products used for the project)
  • Access Library of 100+ tree types to allow for accounting in-life carbon sequestration
  • Model carbonisation  for cementious materials
You can find Net Zero Carbon modeling capabilities in your One Click LCA tools, and to see the them used in practice. For more details, please watch our recorded Net Zero Carbon Design webinar, or ask for a live demo.  

How to Design and Account Net Zero Carbon Buildings

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