The measurement of carbon performance of construction activities: A case study of a hotel construction project in South Wales

The purpose of this research project is to reduce the carbon emissions of construction processes by Measuring, Mapping, Modelling and Managing (4Ms) the carbon performance of construction activities. This particular paper presents the research work and major findings in the first two stages: measuring the carbon footprint of construction activities in building projects; and mapping the carbon emissions from construction activities. A hotel project in South Wales was selected as a case study where the carbon emissions from six categories of construction activities (i.e. management, operations, visitors, deliveries, plant and utilities) were monitored by using carefully designed data collection methods throughout the construction process. Both qualitative and quantitative analysis methods were adopted to distil and map the emissions with construction activities. This study provides a benchmark for the carbon emissions from construction processes. The results show that construction activities generate more carbon than expected. Of the CO2 emitted, materials delivery, operational activities and plant operation account for more than 90 per cent of the total emissions. Activities from management, visitors and utilities only contributed 10 per cent of the CO2 emissions. Carbon emissions from construction processes can be best managed through project planning/scheduling where carbon emissions should be considered as a new criterion for project planning along with time, cost and quality. There are some limitations with the data collection methods adopted in this study. For example, the fuel/CO2 emission conversion rate for plant was obtained from online sources. This rate needs to be validated and adjusted on-site with CO2 measurement gauges for different equipment. Similarly, the fuel efficiency adjusting rates for vehicles also need to be checked and verified constantly. The on-site carbon emission methods, the mapping approaches between the emission and construction activities, and the online system developed in this study (www.constructco2.com/default.aspx) are all embraced by the industry. So far, 76 projects have already subscripted to the online system. This study developed a set of systematic and feasible approaches to measuring and analysing carbon emissions from construction activities. Unlike the existing studies which mainly focus on recording the carbon emissions on-site, this research measured the emissions, and mapped the emissions with construction activities. The online system developed could analyse the data collected and support the contractor to decide in which aspects they should make effort to control the carbon emissions.