Section B - Embodied and Whole Life Carbon
While reducing operational energy reduction is a key priority, whole life carbon costs and benefits over the life of the building also need to be carefully considered so as to avoid allowing practises that unintentionally increase the overall carbon impact of a development.
Whole Life Carbon considers the combined impacts of both operational and embodied carbon emissions over a building’s entire lifecycle. This includes the emissions associated with sourcing, extraction and processing of materials, transporting materials to site, construction of the building, in-use operations (including maintenance, repair and replacement) and end of life (demolition, disassembly and waste processing). The aim of this approach is to move towards a building or a product that generates lowest carbon emissions over its whole life. Whole Life Carbon assessments are therefore considered to be cradle to grave assessments.
As part of our climate resilient position on the built environment, we will be looking at opportunities to incorporate Whole Life Carbon (WLC) approach. This means that the carbon involved in sourcing the raw materials that make construction materials is included in calculation of carbon emissions as is the carbon emitted during construction and operation.
Requirements and guidance for conducting whole life carbon assessments can be found at RICS Whole Life Carbon Assessment for the Built Environment (page 8).
Through a whole building life cycle assessment designers and developers are able to identify the part of the building that have the highest levels of embodied carbon as well as levels of operational carbon and seek to remedy this through reviewing options. The GLA requires that all applications that are referable to the Mayor comply with this standard. In Westminster, to align with our climate priorities, our list of planning validation requirements requires all applications referable to the mayor and major developments involving substantial development to undertake a whole life carbon assessment and our new City Plan will encourage demolition proposals to consider whole life carbon impacts.
Embodied Carbon in the Construction Life Cycle - source: Embodied Carbon – New guidelines from the RICS | Faithful+Gould | UK & Europe (fgould.com)
There are a wide range of mixed use, extension and windfall development types in the city that provide an opportunity to innovate with building materials that have low embodied carbon. Cross Laminated timber (CLT) are panels of wood that have been layered perpendicular to each other to create panels that can be used in the construction process. They can be used for structural (load bearing) and/or non-structural elements of a building and the offsite construction of the panel, made to order for the design of the building has benefits with respect to both off site construction and reduction in emissions. Supporting in principle the use of CLT in construction does not exclude the use of traditional construction materials. Masonry and steel will continue to be important structural elements in Westminster’s built environment, especially where they utilised recycled and upcycled elements. There are opportunities to consider using recycled materials for example aluminium (for roofing) natural fibres (for insulation), cement that incorporates geopolymers, and masonry that utilises by products from the steel industry.