Bath experts call for new thinking and codes of practice to reduce carbon usage

Experts say engineers are forced to significantly over-design and over-engineer our buildings and call for new thinking and codes of practice to reduce carbon usage.

• Buildings are routinely designed to support loads equivalent to many thousands of people more than they can realistically accommodate
• Over-engineering wastes resources – as buildings become more efficient, embodied carbon can surpass that used in normal running
• University of Bath researchers are investigating how buildings can be engineered in a less resource-intensive way
• Researchers join with industry experts to call for existing codes of practice to be revised, and for architects and civil engineers to sign industry equivalent of the Hippocratic Oath
• Discussion took place at the BRE CICM Built Environment: Building a Better World conference in Bath on Tuesday 28 January

New buildings in the UK and Europe need to be built in ways that are far less carbon-intensive, engineers from the University of Bath have warned.

Speaking at the British Research Establishment Centre for Innovative Construction Materials (BRE CICM) Built Environment: Building a Better World conference in Bath, Dr Mark Evernden said that while significant progress has been made in recent years in reducing levels of CO₂ used in the day-to-day running of buildings, the structures themselves ‘embody’ far more carbon than is necessary.

Dr Evernden, Director of Studies in the University’s Department for Architecture & Civil Engineering, said:

We are massively over-designing our structures. At present new buildings are made to meet loading factors far in excess of what they could accommodate.

For example, if we take an average large building of around 16 floors in height, the ventilation capacity can accommodate about 3,000 people and the space planning about 3,750 - while the structural design is made to carry a load equivalent to 85,500 people. It’s far more than ever would be needed.

A modern 50 storey skyscraper may embody as much as 90,000 tonnes of CO₂. If we are serious about reducing CO₂ emissions, we need to tackle this. That will need to be done by adopting a multi-faceted approach that embraces low-carbon alternative materials and by using ‘just enough’ of them and no more.”

A series of startling facts about the construction industry’s part in contributing to global emissions were also shared at the event, including:

• 45% of the world’s annual human-made CO₂ emissions relate to buildings
• 60% of all man-made materials consumed are within the construction industry
• 12% of all human-made CO₂ emissions derive from construction materials such as concrete
• 20% of all construction materials end up in landfill

Professor Chris Wise, Director at Expedition Engineering, echoed Dr Evernden’s thoughts in calling for new industry practices that focus on cutting wastage. He said:

The codes of practice we are using are not fit for purpose. They use the existing built stock as the calibration set. A future code of practice should lay down the need to use the necessary materials and no more.

It’s my view that engineers and architects should sign a code of ethics, equivalent to a Hippocratic Oath, that confirms their first responsibility is to the planet, not profits.”

Cutting wastage in construction is the key aim of the MEICON (Minimising Energy in Construction) project, a collaboration between Bath and the University of Cambridge.

Dr Paul Shepherd, senior lecturer in Bath’s Department for Architecture & Civil Engineering and Deputy Director of the Institute for Mathematical Innovation, highlighted the need to use new technology and modelling techniques to create structures that use no more material than necessary. He said:

We really need to start treating materials as resources that should be spared. We can do this through methods including layout optimisation at the design stage and by increasing off-site automation to cut wastage.”

The conference also featured a keynote speech from Dr Julie Bregulla of BRE Ltd and talks on infrastructure monitoring, applying circular economy principles to the construction industry and digital design and manufacture.