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Embodied Carbon: the impact of building works

On 25th May 2022 the Sustainable Living Group presented talks on Embodied Carbon at a hybrid event – some at the Highgate Society and some on zoom. The talk was hosted by Catherine Budgett-Meakin. The recording is below.

Embodied carbon is “‘carbon emissions associated with energy consumption (embodied energy) and chemical processes during the extraction, manufacture, transportation, assembly, replacement and deconstruction of construction materials or products….. Embodied carbon is usually expressed in kilograms of CO2e per kilogram of product or material. “ – ref LETI p139

Hence, where a product has used low carbon energy during these stages eg during manufacture, (such as solar or geothermal), it will have much lower embodied carbon than if it were subject to high carbon energy, such as (coal).

“The greenest building is the one that already exists” (Retrofirst quote)

The Architects Journal’s Retrofirst campaign.

Then Dermot Barnes – MSc Sustainable Resources talked from his knowledge from his studies and hands on construction.

Than Elspeth Clements BA, BArch(Hons), RIBA, CA, FRSA shared her knowledge from her career in sustainable architecture.


The recording starts with the Retrofirst film

At 3.44 mins Dermot Barnes presents “The Secret Life of Buildings and the Environmental Impacts of Construction”


The full recording of the Embodied Carbon event:



At 20.15 mins Elspeth Clements presents “Embodied Energy in Buildings”

At 40.07 mins the speakers take questions from the floor and from zoom chat.

Further Information and References

The Architect’s Journal campaign: Retrofit above Demolition

The Retrofirst campaign demands these three actions from Government. Note that, the Architects Journal reported in April 2022 on the VAT cuts on energy saving products in the 2022 Spring Statement, noting that “he fell short of announcing a wholescale, and much-demanded, reduction of VAT on all refurbishment work” – see below for details.


Some reduced VAT rates on installation and products.

Guidance  Energy-saving materials and heating equipment (VAT Notice 708/6) for Installation of energy saving materials was updated following the Spring Statement on 23rd March 2022. It lists the items eligible for zero rating from 1st April 2022 as:

– controls for central heating and hot water systems
– draught stripping
– insulation
– solar panels
– ground source heat pumps
– air source heat pumps
– micro combined heat and power units
– wood-fuelled boilers
– wind turbines
– water turbines

All other items remain at the previous VAT rates.

MPs say Demolishing and rebuilding creates double emissions by necessitating the manufacture of two lots of construction materials.

BBC 26th May 2022 here .

Construction Industry proposed ‘Part Z’ regulation

“We have written Part Z and its accompanying Proposed Document Z as a proof of concept of the regulation that’s needed in the UK. If enacted, Part Z would ensure that embodied carbon is assessed on all projects, as part of a comprehensive whole life carbon assessment.

It would also ensure that the embodied carbon emissions are then capped on all major construction projects.”


Standards for Environmental Product declarations

The EU standards Sustainability of construction works – Environmental product declarations – Core rules for the product category of construction products were revised in 2019. The UK has said that it will maintain equally high environmental legislation as the EU.

The environmental impact of products used, and discarded, at each stage of construction and disposal have to be calculated to arrive at a total, requiring specialist software and trustworthy data such as carbon emissions per product.

How did ‘Save Britain’s Heritage’ ensure that demolition comes under the EIA process?

The 2011 ruling on demolition: “demolition which is considered to have significant effects on the environment will be subject to the Environmental Impact Assessment (EIA) process.“


How much building material becomes ‘waste’ in north London?

The North London Waste Plan at page 24 has Construction, Demolition and Excavation quantities in this table:


How is London Councils advising Local Authorities?

The London Councils Retrofit Housing Action Plan at page 78 here covers  ‘Enhance planning to facilitate low carbon retrofit, including in conservation areas.’


London Energy Transformation Initiative (LETI)

The LETI Embodied Carbon Primer  is here.

The LETI Circular Economy one pager ie.

The LETI  presentation on the work by the UKGBC, in summer 2021 by LETI and the Whole Life Carbon Network, supported by the RIBA on the survey of profressionals on ‘Net Zero Buildings’ is  here .