A review of UK greenhouse gas emissions from recent built-environment projects

The greenhouse gas emissions of a range of current and recent built-environment projects in the UK and internationally were studied to give a benchmark of current levels and to identify where improvements could be made. A top-down and bottom-up approach was used, considering published data on projects over £1 billion and database estimates for smaller projects and individual structures. In total, emissions of 14 projects, 117 bridges and 120 buildings were studied. It was found that emissions generally rose with increased project length, area and cost, but there was a significant variation in the results. It was also found that the ‘carbon emissions intensity’ of projects is significantly higher than offsetting options like tree planting, such that design optimisation and value engineering are far more cost-effective for reducing emissions and achieving ‘net zero’.