Carbon Counting 2011

In 2009, some of the largest M & E contractors asked the ECA and the Heating and Ventilation Contractors’ Association (HVCA) to tackle a growing range of questions from buyers about project-based carbon emissions.

  • Reducing M & E contractors’ costs (members spend too much time dealing with different enquiries about their carbon emissions);
  • Reducing the risk of duplicated or incomplete carbon counting;
  • Improving targeting, benchmarking (for example, spotting where the biggest carbon impacts are and what successfully reduces them) and reporting; and
  • Allowing clients and contractors to set realistic carbon budgets for future projects

The associations knew that numerous ‘carbon footprinting’ methods existed, and the challenge was to to come up with a new one, but to work with others to find a widely acceptable method for measuring project carbon emissions. The first step was to get an accurate view of the current situation. the ECA and HVCA decided that an effective way to communicate across the industry was to team up with the Construction Industry Research and Information Association (CIRIA).

Industry Survey

Together, the ECA and HVCA issued an industry-wide survey to buyers (those seeking carbon footprinting information) and suppliers (those providing the information). The survey, which was carried out in spring 2010, comprised 34 questions, including;

Questions to clients:

  • What are the main drivers for seeking to measure the carbon footprint of construction projects? (for example, ISO 1400)
  • What key documents/organisations have helped/influenced your approach to carbon footprinting?
  • Given a choice, what data source do you prefer for assessing your project-based carbon footprint?
  • At what project stage(s) do you require carbon footprinting information?

Questions to suppliers:

  • At what stage(s) of the project are you asked to provide carbon footprinting information?

More than 50 organisations from across the industry replied, providing the ECA and HVCA with a valuable snapshot of how the supply chain approaches carbon footprinting. This feedback gave us useful information, and something that we could share with the rest of the industry.

As we developed links with other industry players, it became clear that we were not the only group looking at project-based carbon footprinting. In the summer of 2010, the Strategic Forum for Construction (SFfC) and the Carbon Trust had produced an impressive report on how to reduce construction carbon emissions , notably those from projects. In the autumn, we pooled our information and joined the SFfC’s carbon sub-group, to help bring home an industry-wide project carbon method.

Industry-wide carbon group

The ECA is an active participant in the SFfC carbon sub-group, which agreed that a project-based carbon metric should:

  • Be easy to measure;
  • Be relevant to all sizes of construction project and contractor;
  • Reflect current understanding of the main sources of carbon emissions during projects; and
  • Fit with existing carbon footprinting protocols such as ENCORD, the Global Reporting Inititiative and Greenhouse Gas (GHG) protocol.

Proposed site-based carbon questions

Subject to final consultation , the new method for project-based carbon footprinting is expected to be launched by early summer 2011. The method is developing along the following lines;

  1. Collect the data-either before/during construction and/or on completion of the project:
    • The amount of energy expected to be used/used on-site since the start of the project e.g. electricity (kWh), diesel (litres), gas LPG or LNG (kg) and other types; and
    • The value of the project.
  2. Calculate carbon emissions per type of energy use:
    • Energy from renewable is expected to be classed as having a zero CO2e per kWh emission factor.
    • To calculate CO2 e emissions: CO2e emissions=Energy consumption (kWh) x Fuel emission factor (kg CO2e/kWh)
  3. Normalise the results:
    • The performance score is calculated using the formula: (CO2e emissions (kg CO2e)/Project value (£) x 100,000

The agreed scope of project work for the new carbon footprinting method is:

  • Deconstruction;
  • Enabling works and remediation;
  • On-site plant and equipment;
  • Site accommodation;
  • Fit-out and finishing;
  • Maintenance and repair; and
  • Major refurbishment and renovation.

What’s not included…..

After extensive discussion, the carbon sub-group agreed not to include the following aspects in its proposed site-based method (though the information can still be collected and used alongside):

  • Off-site manufacturing and assembly-these should be reported separately, rather than by project;
  • Freight transport – this is covered by a parallel SFfC carbon sub-group;
  • Allocating emissions from corporate offices and business travel to a given project;
  • Embodied carbon – again, data can be added to that obtained from the site-based method; and
  • Unless renewable energy is generated and used on-site, project-based carbon savings (e.g. from green tariffs) should not be claimed.

The carbon sub-group also decided to benchmark good and best practice during the construction phase. The suggested metrics include:

  • Domestic buildings – tonnes CO2 per square metres gross floor area (GFA)
  • Non-domestic buildings – tonnes CO2 per m2
  • Infrastructure (area) – tonnes CO2 per m2

The ECA will also be involved in any future development of planned benchmarks for refurbishment, repair and maintenance.

Strategic Forum carbon action report

The SFfC’s 2010 report highlights 11 areas for action, to achieve a 15% reduction in carbon emissions (compared with 2008). These are:

  • Energy efficient site accommodation;
  • Efficient use of construction plant;
  • Earlier connection to the grid;
  • Good practice energy management on site;
  • On-site measurement monitoring and targeting;
  • Fuel-efficient driving-freight driving and renewable transport fuels;
  • Construction consolidation;
  • Sharing knowledge about alternative sustainable fuels;
  • Reducing the transport of waste;
  • Business travel fleet management and modal shift; and
  • Good practice energy management of corporate offices.

Using information from the Department for Business, Innovation and Skills (BIS Low Carbon Construction Innovation Growth Team, the SFfC/Carbon Trust report estimated the main site-related carbon impacts to be:

SFfC project –based carbon footprinting steering group

The industry-wide carbon sub-group is chaired by Jon de Souza of Constructing Excellence. In addition to the ECA, representatives on the group include:

  • The Strategic Forum for Construction;
  • The Construction Product’s Association;
  • The Civil Engineering Contractors’ Association;
  • The UK Contractors’ Group (UKCG – of which ECA is also a member);
  • The Construction Industry Council;
  • CIRIA/HVCA; Defra; The Carbon Trust; BRE; Glenigan; Parsons Brinckerhoff; Atkins; Arup; WSP Group; BAM Construct; Laing O’Rourke; and Lend lease.

Carbon – three key definitions

Carbon dioxide equivalent

Essentially, ‘carbon dioxide equivalent’ (CO2) converts the masses of various greenhouse gases (e.g. methane, sulphur hexafluoride) to the mass of CO2e of methane is around 25 times that of carbon dioxide.

Carbon footprint

The total amount of greenhouse gases (mainly, but not just, carbon dioxide) emitted directly or indirectly due to (project) activities. The carbon footprint is usually expressed in equivalent tonnes of either carbon or carbon dioxide (CO2e). The SFfC has opted to use CO2e.

Embodied carbon

Embodied carbon describes the carbon dioxide generated during parts of the life cycle of a product or equipment (that is, it does not apply to energy consumed or generated during product use). It is usually based on pre-calculated CO2e. Embodied carbon is similar to embodied energy.

For more sustainability-related definitions, see the ECA ‘A-Z of Sustainability’ at

Millions of tonnes (Mt) of carbon dioxide

  1. Site activities – including site offices (2.01 Mt)
  2. Freight transport (1.86 Mt)
  3. Waste removal (0.60 Mt)
  4. Off-site assembly (0.27 Mt)
  5. Off-site offices (0.27 Mt)
  6. Business travel (0.08 Mt)

This work showed the main areas that need attention (site activity and fright) and where reductions would only make a marginal difference (for instance, business travel).


Overall, the proposed project-based carbon footprinting method should greatly improve supply chain enquiries to specialist contractors, while the work above will help to focus on practical reductions to site-based carbon emissions. Barring any last minute hitches, the new methodology should be included in the Construction Industry Key Performance Indicators (KPI’s), compiled by Constructing Excellence, in its survey of construction projects completing in 2011. Beyond the ECA’s continued contribution to the SFfC carbon sub-group, our next challenge will be – as it is with pre-qualification – to help ensure the widespread application of this new method throughout the suppy chain.