This article looks into whole life carbon through the RIBA stages. It is based on the excellent book Targeting Zero by Simon Sturgis. It is not just one of the best books that I have read on sustainable buildings, but is potentially one of the most important books on sustainability that I have come across, given the large percentage of carbon emissions associated with buildings.
Whole life carbon is an analysis based on the sum of the embodied and operational carbon emissions.
Embodied carbon emissions relate to the sourcing of raw materials, their transportation and fabrication into building components which are then delivered to site and assembled.
Operational carbon emissions are the emissions of carbon dioxide during the operational or in-use phase of a building.
The thinking is that by considering these two aspects simultaneously as part of a whole life carbon analysis, you optimise trade-offs between the two, to maximise carbon emissions reductions. Looking at them in isolation can lead to decisions which may actually increase carbon emissions.
The RIBA Plan of Work is a document that outlines all stages in the planning, design and building process, from conception to completion on site.
This article will go through each of these stages in turn and look at Simon Sturgis’s analysis of how whole life carbon can be considered at each turn.
RIBA Stage 0 – Strategic Definition
Simon provides a number of reasons why a client would be interested in whole life carbon analysis.
- Producing a specifically low carbon building
- Pre-empting changes in standards and legislation to future proof the asset
- Marketing advantages
- Corporate social responsibility
- Circular economic considerations
- Added value
- Resource efficiency
- A desire to mitigate climate change impacts
RIBA Stage 1 – Preparation and Brief
At this stage, a whole life carbon assessment would require a life cycle assessment. This encourages long term thinking about the building’s fabric and functional performance past practical completion.
RIBA Stage 2 – Concept Design
To be successful, whole life carbon thinking should be embedded within the design process from the outset.
The following life cycle considerations should be taken into account at this stage:
- Climate change
- Future building flexibility
- Intended life and durability
RIBA Stage 3 – Developed Design
The carbon intensity of the various structural and envelope options should be taken into consideration. Carbon budgets can be created using cost data available at this stage. This can be used as a baseline which improvements can be judged against.
RIBA Stage 4 – Technical Design
At this stage, building on the work done in the previous stages, low carbon choices are now integrated into the detailed drawings and documentation. It is important that the contractors selected are clear about the low carbon aims and aspirations of the project and are able to deliver on these during the construction phase.
RIBA Stage 5 – Construction
A key issue here is monitoring the actual carbon impacts of the project and how they relate to the carbon budget.
Reporting would be required at intervals of 3 to 6 months to ensure that contractors stay on top of the data and the project stays on track and within the carbon budget.
RIBA Stage 6 – Handover and Close Out
At this stage a final carbon review of the as built information would be undertaken to create an assessment of the whole life carbon impacts of the project.
There is an opportunity to learn lessons from any variations between the design stage carbon budget and the as built records.
RIBA Stage 7 – In Use
At this stage a post occupancy evaluation should be done to take account of the whole life carbon impacts.
How a building evolves over its life is very much down to decisions made at the design stages.
What you need to know
This article looked into whole life carbon through the RIBA stages. It was based on the excellent work of Simon Sturgis and I encourage all my readers to buy and read a copy of his book Targeting Zero.
What I hoped to show in this article is that there are opportunities to reduce whole life carbon throughout the RIBA stages. It begins with a client who is interested in the subject matter and willing to expend resources to investigate low carbon opportunities.
All of the gateways flow into one another and it is important that a decision is taken at the beginning to prioritise whole life carbon impacts.
Thank you for reading,
By Barnaby Nash
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