First Steps: What is Construction's Carbon Footprint?

Positive outcomes of greener construction products and services can be measured in terms of electricity and water savings, improved health, and reduced consumption of resources.  All of these outcomes can be compared to one another using equivalent units of carbon dioxide emitted directly or indirectly as a result of an activity, or simply, “carbon”.  The amount of carbon is measured in terms of a “carbon footprint”. 

Green construction not only yields the benefits we just mentioned, but with a straight-forward calculation, green construction also yields a positive contribution to climate change.  By framing these efforts using the concept of carbon, developers, builders, and individuals alike can move closer toward being Carbon Neutral, where the net carbon footprint of an activity becomes zero.

The first step in understanding one’s carbon footprint is conducting a greenhouse gas assessment.  Greenhouse gases are the compounds which contribute to climate change, with carbon dioxide being the most voluminous greenhouse gas.  The Big 5 team is gathering data from across the value chain to understand, calculate and analyse the carbon footprint of last year’s Big 5.

The Big 5 believes that leadership is needed today to help the industry choose to take action.  First, the event has committed to taking steps to achieve CarbonNeutral® status. 

Second, dmg :: events will estimate the expected footprint of the 2009 event.  After identifying and implementing emissions reductions, The Big 5 will purchase carbon offsets to net the event’s emissions to zero.  After the event, dmg :: events will conduct an assessment to confirm the impact of these reductions. 

This process will affirm the evolving green credentials of the The Big 5 and the construction industry and serve as an example to exhibitors, sponsors, attendees and speakers, as well as the UAE.

The Big 5’s carbon footprint is in relation to that of its host country, the UAE, which is among the highest per-capita emitters of greenhouse gases in the world (see insets). 

We consider these figures a proxy for the level of responsibility an industry has toward the environment.

Globally, the construction and operation of buildings is a significant contributor to carbon emissions; in 2002, over 3.2B tonnes of CO₂ equivalent were put into the atmosphere by this industry.  Breaking this figure down further can be conducted in many ways, which EcoVentures provides  in its day-to-day advisory work.  As an example of how an individual contractor can think about carbon, we provide the breakdown of the carbon footprint of the construction of a 3-bedroom semi-detached home.



















The UK has a great deal of data on construction’s carbon footprint.  Lighting and heating buildings generates 50% of Britain's carbon dioxide emissions while the production of building materials accounts for a further 10%.  And it is not just carbon emissions that are the problem. The construction industry generates one third of all the waste in Britain while 20% of new building materials on the average building site are simply thrown away at the end of the job.

One concept to consider in calculating the carbon footprint of construction is embodied carbon, which is a measure of the carbon released when a product is manufactured, shipped to a site and installed.  For some products, there is a long trail including such things as mining the iron ore and its transportation to a smelter, the manufacture of steel and forming it into structural members, then transportation to the jobsite. Carbon is released in every step.

The greatest contribution to embodied carbon for both housing types comes from cement-based materials (poured concrete, concrete blocks and pre-cast concrete elements).  Cement-based materials contribute in excess of 50% of the carbon footprint in construction.

Construction’s carbon footprint is useful to know so that we can make cost-effective reductions in carbon emissions individually and collectively.  A number of players have already taken action on carbon to reduce their carbon footprint.

London.  Berkeley Homes is a construction and home builder in London who sought the help of The CarbonNeutral Company in order to fully reduce and offset the carbon emissions associated with building a 518-unit residential development called West 3.  By switching all of the Berkeley Homes to renewable energy and connecting all of the new apartments to a green electricity tariff, 1700 tonnes of carbon were reduced, or 18% of the total project emissions. Berkeley’s remaining 7000 tonnes of carbon were neutralised through a combination of forestry and climate friendly energy schemes, making the company Carbon Neutral.

Singapore.  EnGro is working to meet carbon footprint standards of the Singapore Environment Council’s Green Labelling Scheme using its unique cement.  An independently assessed carbon footprint report will provide transparent means to gauge carbon emissions of EnGro’s products.  Under the guidelines, each cement player in Singapore is required to present an independently audited report from a third party to confirm that their products are made from concrete that utilises waste materials, such as blastfurnace slag.