The building industry is responsible for 14 gigatons of greenhouse gas emissions every year with construction accounting for 38 percent of total global emissions. Our High Performance Buildings Leader Victoria Watson shares valuable insights into the latest strategies and approaches for assessing and reducing both embodied and operational carbon in tall buildings.
The size of our carbon challenge
In 1950 the world emitted 6 billion tonnes of CO2. In 2019, buildings alone contributed to 38 percent of emissions, equating to 13,850 million tonnes. In terms of annual global CO2 emissions, the built environment and construction accounted for 47 per cent, 27 percent from building operations, 10 percent from building materials and construction and 10 percent from other industry construction. This clearly illustrates the size of our carbon challenge. But it doesn’t stop there. By 2060, the global building area is set to have increased by 230 billion meters squared of new floor area, the equivalent of adding an entire New York City to the world, every month, for 40 years.
How this challenge may evolve for buildings
By 2040, if as an industry we don’t make any interventions, total carbon emissions from new construction globally will account for 57 percent of embodied carbon and 43 percent of operational carbon. This is concentrated in the use of just three materials: concrete, steel and aluminum. Collectively these account for 23 percent of total global emissions (concrete 11%, steel 10% and aluminum 2%). Therefore, the built environment as a sector has a real opportunity to be part of the solution not just the problem.
Our responsibility as an industry
Many countries and states have introduced their own regulations and standards, alongside several industry certifications and rating levels which are driving improvements across the sector such as LEED Energy, LEED Zero, Zero Carbon and Code Zero, but we should proactively look to do more, not just wait for mandates and enforcement to be introduced. There’s also the social cost of carbon on health and inequality that must be considered.
The opportunities
If we’re to meet the 1.5 degree climate target by 2040 as laid out in the Paris Agreement, we must eliminate all CO2 emissions from the built environment.
Use this handy starter checklist of items to consider for applicability on projects:
1. Operational carbon demand reduction
- Building electrification
- High performance envelope
- High efficiency HVAC
- High efficiency lighting
- Smart buildings
- Carbon charettes
- Integrative design
- Catering electrification
- Heat pump water heaters
- Heat pump packaged units
- Heat recovery chillers
- Simultaneous heat/cool recovery
- Passive design
- Overhang shading
- Shading fins
- Optimized massing
- High performance glazing
- Heat recovery ventilation
- Operable windows
- Thermal bridging
- Envelope air tightness
- High efficiency chillers
- High efficiency heat pumps
- High efficiency systems
- Radiant systems
- Grey-water recycling
- Rainwater harvesting
- Wrap around heat pipes
- Sewage heat recovery
2. Operational carbon offsetting
- Renewable energy
- Solar panels
- Building integrated solar panels
- Car port solar panels
- Roof top solar panels
- Solar thermal water heating
- Geothermal heat pumps
- Battery energy storage
- Thermal energy storage
- Green power
- Renewable energy certificates
- Direct access green power
- Community solar
3. Embodied carbon design
- Building re-use
- Material re-use
- Optimized structure for carbon
- Optimize concrete drying time
- Optimize concrete strength
- Refrigerant leakage prevention
- Carbon sequestration
- Optimize HVAC ducting material
- Using local materials
- Using regional manufacturers
4 Material specification
- High recycled content steel
- Low embodied carbon wall finishes
- Bio-based flooring
- Low embodied carbon insultation
- Low embodied carbon interior paints
- Low embodied carbon gypsum board
- Limiting epoxy and paint usage
- Low embodied carbon CMU Blocks
- Low embodied carbon cold-formed steel
- High recycled content concrete
- Higher durability products
- Longer service life products
- Carbon sequestered ingredients
- Materials with planned end-of-life
- Materials with take-back program
- Reduced floor to ceiling heights
- Bio-based gypsum fiber panels
- Water-based epoxy floor finish
- Carpet tiles with recycled content
- HDPE waterproofing membrane
- Concrete with high ground granulated blast-furnace slag (GGBS)
- Ready-mix concrete with high supplementary cement material (SCM) content
- Warm-mix asphalt with additives
- Mineral wool batt insulation
5. Carbon related process improvements
- Environmental performance declarations (EPDs)
- Embodied carbon assessment
- Require electric construction equipment and piloting
- Transparency on embodied carbon tools and databases
- Setting an embodied carbon reduction target
- Access to appropriate embodied carbon benchmarks
- Stretch codes
- Lessons learnt
- Knowledge sharing
- Mandating third party verification EPD's from vendors
- Carbon certification
6. Facilitation of wider decarbonization
As an industry we have an opportunity to be leaders in decarbonization, to take technologies from bleeding edge to technically proven and implantable solutions. As the world grapples with decarbonization and the utility grid looks to modernize to be able to take on the challenge there are potential opportunities for buildings to help facilitate wider decarbonization. The primary storage capabilities that most homes currently have is storage water heaters, but with smart controls we may start to consider “buildings as batteries”. They can shift additional demands to off-peak storage by integrating additional thermal storage, home battery storage and battery storage for example to become a flexible load for a modernized grid.
As an industry we have the power, knowledge, and expertise to decarbonize the built environment. The time is now to come together and achieve this at the accelerated speed needed to achieve our goals.