Whole life carbon

Whole life, building life cycle or full building carbon assessments consider the combined impacts of both operational and embodied carbon emissions over a building's ent9ire lifecycle, including repair and replacement cycles. Carbon in this case usually refers to carbon dioxide equivalent (CO2e) which is a metric measure used to compare the emissions from various greenhouse gases on the basis of their global-warming potential (GWP), by converting amounts of other gases to the equivalent amount of carbon dioxide ( often shortened to just carbon) with the same global warming potential.

Operational emissions from the use of a building or asset are divided into direct emissions, such as a wood burning stove or gas cooker, called Scope 1 emissions and indirect emissions, from for example electricity used in the dwelling but produced via a coal fired power station, which are called Scope 2 emissions. Embodied or Scope 3 emissions are effectively all other emissions that might relate to the construction of a building, the carbon emissions resulting from the materials, construction and the use of a building over its entire life, including its demolition, disposal or re-use.

A Whole Life Cycle Carbon assessment provides a true picture of a building's carbon impact on the environment and studies will normally divide the whole life assessment into system boundaries from cradle to cradle according to the standard BS EN 15978-1 Sustainability of construction works - Methodology for the assessment of performance of buildings. - Part 1: Environmental Performance. This standard looks at a number of different impact categories across a building life cycle, how ever the same principles are used when the only impact category being studied is carbon equivalent emissions.

Studies have shown that when a building is assessed over a full life cycle of 60 years the carbon emissions that are associated with all processes up to its final completion can be up to 50% of the buildings associated carbon emissions.

There are a number of key documents that are freely available and help explain what whole life carbon is, why it is important and how to calculate it for a building design, some of these are given below.

• The Royal Institution of Chartered Surveyors Whole life carbon assessment for the built environment - RICS V2
• The Royal Institution of British Architects Embodied and whole life carbon assessment for architects
• The Association of Sustainable Buildings Products Whole life carbon measurement: implementation in the built environment
• Low Energy Transformation Initiative https://www.leti.uk/carbonalignment
• The Institution of Structural Engineers https://www.istructe.org/IStructE/media/Public/TSE-Archive/2020/A-brief-guide-to-calculating-embodied-carbon.pdf

NB PAS 2080:2023 Carbon management in buildings and infrastructure, second edition, published by The British Standards Institution in March 2023, defines whole life carbon as the: ‘sum of greenhouse gas emissions and removals from all work stages of a project and/or programme of works within the specified boundaries…. NOTE 1 This includes GHG emissions and removals within the project/programme boundary, as well as emissions/removals between the project/programme and study boundary. NOTE 2 Not to be confused with “design life”, which is the life expectancy of the material/product/asset, as defined by its designers within its specified parameters. Typically, whole life is longer than design life. NOTE 3 Whole life carbon considerations for a project and programme of works are wider than the typical life cycle assessments account for, particularly when considering carbon emissions/removals in their influence at a system level.’

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[edit] Related articles on Designing Buildings

• Carbon dioxide equivalent
• Carbon.
• Carbon dioxide.
• Carbon footprint.
• Embodied energy.
• Energy consumption.
• Energy Performance of Buildings Directive.
• Energy targets.
• Greenhouse gases.
• The sustainability of construction works.