Reconstructing a sustainable built environment: retrofitting over rebuilding

Decarbonising construction

Before we look at the merits of retrofitting, it is worth considering the overall challenge facing our sector. 

Decarbonisation refers to measures which individuals, businesses, organisations, and whole industries can take to reduce the levels of carbon emissions they produce – or contribute towards. 

There is naturally some complex maths and science in the background, but the manufacturing of building materials and construction of buildings requires energy and processes which contribute to climate change.

Why it’s better to retrofit than rebuild

In carbon terms, the construction sector is a ‘linear economy.’ Materials are sourced, used and then – once the building becomes unfit for purpose – disposed of. This is increasingly unsustainable.  

In March 2021, the Mayor’s 2021 London Plan stated, “major development should be net zero carbon” and goes on to outline the requirement for Mayoral referable schemes (an application for planning permission of potential strategic importance) to calculate whole life cycle carbon emissions in London.  

Chris Cummings, Director of Savills Earth, says;

“The loudest voices are currently shouting retrofit only. We need to return to retrofit as a first option but ensure a broader conversation. If you make a decision based purely on carbon usage you may not provide what communities need or consider peoples’ health and wellbeing – and that’s not truly sustainable.” 

On balance, the industry is moving towards retrofitting over rebuilding, with the key benefits being:

• Retrofitting buildings contributes to the reduction of carbon emissions through the concept of embodied carbon. Embodied carbon is the greenhouse gas emissions associated with the construction and initial materials of a building. When retrofitting a building, the existing structure and materials are utilized, reducing the need for new construction materials and the carbon emissions associated with their production and transportation.
  
• Existing buildings account for nearly 40% of annual global greenhouse gas emissions, and buildings as a whole make up around 21% of global emissions. Whilst ongoing carbon emissions from the building (such as heating, cooling, and lighting) might be greater than a state-of-the-art replacement, this is dramatically offset by the avoidance of new carbon emissions.
• Carbon emissions from new materials and construction are negated.
• Carbon emissions from the recycling or disposal of demolished materials are also avoided.
  

Every case is different and there will always be strong arguments – practical, moral, and environmental – for replacing older structures. 

However, retrofitting and refurbishing has a big part to play in the construction industry achieving decarbonisation and becoming more sustainable. 

Architects, designers, project teams, building contractors, developers and other property professionals can use 2D plans and 3D models to make informed choices on whether a project can be decarbonised via improvement rather than demolition and rebuilding.  

The accurate data and measurements help teams redesign the structure and plan the most carbon-efficient way in which the work can be completed. 

BIM models allow for greater collaboration, as all members of a project team can virtually view and work on the project. Site visits are reduced, again helping limit carbon emissions.

Accurate modelling also reduces the risk of errors and reworks which contribute to carbon emissions through wastage and additional activity.

Quality.org states

“Up to 70% of total rework experienced in construction and engineering products are a result of design-induced rework.”  

How can CADS help support decarbonisation and retrofitting?

With over 35 years’ experience, we provide the very latest in surveying services and technology for a wide range of projects. 

As well as BIM-ready surveys, we can deliver traditional topographic surveys, drone surveying, GIS (Geographic Information System), asset mapping and more. 

We have trusted experience working with building contractors, landlords and estate managers, architects, designers, and project teams across the UK, providing accurate survey data and models to help decarbonise existing structures through retrofitting. 

Get in touch today to find out more.