How can we Decarbonise the Built Environment?

15 Mar 2022

Over the last three months we’ve been writing about three major issues which affect our industry but which we don’t seem to be able to deal with. The first is digital transformation, the second building safety, and this article is about the third – the decarbonisation of buildings.


In the UK, the Committee on Climate Change has recommended that all buildings must be net-zero to deliver the Government's goals. To achieve net-zero we must eliminate or offset both embodied carbon and operational carbon in buildings.

Embodied carbon is the Carbon emissions associated with materials and construction processes during the construction and refurbishment of a building or infrastructure.  The World Green Building Council calculates that embodied carbon in the built environment accounts for about 11% of total global emissions.

Operational carbon is the emissions associated with energy used to operate the building or infrastructure, i.e. during its life. The operation of buildings alone creates 23% of UK emissions.

Embodied Carbon Reduction – Build nothing or build less

The Treasury reviewed options for reducing embodied carbon in buildings and infrastructure in their Infrastructure Carbon Review of 2013. They concluded that there are four strategies for reduction and the sooner you start in the process the more carbon you can save:

  1. Build nothing – challenging the root cause of the need to build and exploring alternative options
  2. Build less – maximising the use of existing assets to reduce the need to build new
  3. Build clever – minimising resource consumption, using low carbon materials
  4. Build efficiently – eliminating waste and embracing new construction technologies.

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Strategies for eliminating embodied carbon – Infrastructure Carbon Review, HM Treasury 2013

To reduce embodied carbon, we need to begin by reducing the demand to build new, and then when we do build, do it efficiently and intelligently.

Does this concept sound alien to the established culture of always building new? It does to us.

Operational Carbon Reduction – Reducing Demand

73% of operational carbon emissions from buildings are direct emissions via the burning of fossil fuels to produce heat; the remainder is from grid electricity. To reduce operational carbon, it is necessary to reduce the demand for energy in our buildings, particularly when the demand for renewable energy exceeds the available supply.

Let’s look at three strategies in more detail and what might be stopping them happening effectively.

1. Waste Reduction

Waste costs the construction industry an estimated £11 billion per annum and emits 3.5 million tonnes of CO2.

We need to reduce waste in the production process for materials, in on-site processes, in the operation of buildings and at the end of life of buildings. Nearly 5 million tonnes of non-hazardous construction and demolition waste in the UK went to landfill in 2016, and the construction sector now has a target of zero avoidable waste.

To reduce operational carbon, we also need to reduce energy waste, improving the performance of buildings and reducing energy use in the production of materials and built assets themselves.

What is preventing Waste Reduction?

We think there are three major barriers to waste reduction in the built environment:

  1. Lack of understanding of embodied carbon generally and the motivation and opportunity to reduce it.
  2. Complexity, lack of clarity and support on the right way to measure carbon – multiple initiatives and a complex regulatory and standards environment
  3. Lack of understanding of end-of-life buildings waste control as a concept.
  4. Lack of information about building components, what they are and where they are. We discussed this in our article on digital transformation.

Digitalisation can help with collecting and organising data on energy and material flows. Historically, companies have mainly used data to improve labour productivity, but digitalisation can now be used to drive out energy inefficiency in production.

(Delivering Net Zero Through Digital: Policy Connect, the All-Party Parliamentary Group for Manufacturing, and the Institution of Engineering and Technology, 2021)

2. Circularity

The concept of waste elimination comes to its zenith in the concept of circularity, or the circular economy.


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The UN Environment Programme argues that circularity and sustainable consumption and production are essential to delivering on every multilateral agreement, from the Sustainable Development Goals to the Paris Agreement to the post-2020 global biodiversity framework.

One of three principles of the circular economy is to circulate products and materials at their highest value. This means keeping materials in use, either as a product or, when that can no longer be used, as components or raw materials. This way, nothing becomes waste and the intrinsic value of products and materials are retained.

The production and use of assets in the built environment is largely linear. What is preventing circularity in the built environment, beyond a few pilot programmes?

What is preventing Circularity?

We have identified four barriers to implementing a circular economy in construction. Perhaps you can think of others:

  1. A commercial preference for building new, with new materials and on new sites – there is no desire to reuse materials as it is cheaper and lower risk to use new ones.
  2. Lack of information about the products in built assets – in other words, not knowing what is there, that can be reused.
  3. Lack of supply chain transparency more generally – the tendency is to withhold information rather than share it.
  4. Lack of an established market for the reuse of products and materials – so that it become commercially attractive.

3. Retrofit – The Elephant in the Room

We need to both reduce the amount of building we do and reduce the demand for energy in our buildings. And new build will not deal with our existing estate; 80% of the buildings that were around 5 years ago will still be there in 2050. Retrofit is therefore key to achieving net zero in the built environment.

Retrofit is the process of improving buildings and infrastructure with elements and technology which were not available when they were built. It is not simply about saving on carbon emissions by not building new, but also enables

    1. Cost savings by reducing energy consumption
    2. Buildings to become healthier places with better air quality.

Equally retrofit doesn’t only apply to residential buildings. In 2016 the Low Carbon Innovation Coordination Group found that innovation in the non-domestic buildings sector could save 70 million tonnes of CO2 and save £14bn in energy costs by 2050.

There is a huge need for retrofit with 27 million homes and 2 million non-domestic buildings to decarbonize in less than 30 years. And yet, there doesn’t seem to be a co-ordinated approach to achieving this requirement in our existing buildings. Professionals fear that it will not happen. What are the barriers to change?

What is preventing Retrofit?

There are a number of reasons why retrofitting existing buildings is seen as less attractive than building new, energy efficient ones.

  1. Complexity – existing buildings are complex and risky to work with.
  2. Multiple initiatives with poor reputations – and a lack of a coherent single governing direction (and the opportunity for commercial advantage to be taken as a result).
  3. Lack of information in the form of a digital foundation for our building stock – which would reduce uncertainty.
  4. Lack of an established market for consumers and building owners, their advocates or for contractors and installers.

Where to from here? Join Our Call:

We aren’t implementing the key strategies of waste reduction, circularity and retrofit at scale, despite a huge number of initiatives, publications, and articles about it. Why not? What is stopping us, and what can be done about it?

As Rome wasn’t built in a day, we want to reflect, and try and find the right direction. Let’s ponder three questions:

  1. What is the big win for the built environment and construction to improve sustainability?
  2. Is circularity achievable for buildings? What do we need to do it?
  3. What do we need to make Retrofit happen?

Join us on Teams to discuss this article on Friday 18th March at 2.30pm.

Sign up here for your place.

Read: Digitisation for Construction Product Manufacturers: a Plain Language Guide

The guide aims to help decision-makers in manufacturing identify:

  • Why structured data is important.
  • How to avoid poor investment decisions.
  • How to protect their future with a step by step process to set priorities and implement information management across the supply chain for their products.

Read the guide here:

Check out our tweets at #ManufacturersPLG.

This work has been developed by the IET with support from BEAMA, to download the IET Plain Language guide visit the IET website 

LINK to IET article

About ManufacturersPLG Team

We are the Plain Language Guide Editorial Team.
We have produced a guide to digitisation for construction product manufacturers and are blogging our investigations of the issues around information management for construction product manufacturers and the wider built environment in the UK and Europe.Manufacturers produce a significant part of the information required to bring about a safer construction industry, but this information is currently not structured or shared in a consistent way.

If industry is to meet the challenges of a digital future, avoid a race to the bottom and respond to the requirements of a new building safety regulatory system, we need manufacturers to structure and share their data safely.