Through constructco2 we can now start to get an understanding for the level of CO2 emissions that arise solely from the construction activity, ie those within the control of the construction team. Overall this is currently looking like 98kg per £100,000 contract value, or 1tonne for £1m. There are of course variances in this, and as soon as we have more projects completing a better picture will emerge.
This figure is arrived at through measuring the carbons arising from personnel travel, the material and waste transport emissions along with the fuels and energy used on a project. The front page of constructco2 shows a real time breakdown across these areas for projects using the tool.
But what does a tonne of CO2 look like? Borrowing an idea and concept from Carbon Coach Dave Hampton, I often use balloons in my sustainability workshops, with each delegate blowing up a party balloon. Each one of which represents about 10g of CO2. Imagine a medium sized workshop room / classroom filled with balloons and we starts to get a feeling for what a tonne can look like.
Now a very useful visual measure has been developed by University of Leicester, sponsored by Willmott Dixon, where a tonne of carbon is represented as a cube larger than the average house at 560m3 (Although not new as a CO2 Cube created from 12 shipping containers to form the equivalent of a three-story building, was used to demonstrate what a tonne can look like at Copenhagen in 2009)
So for every £1 million of contract value we are emitting the equivalent of a large family house. The SfC Strategic Forum for Construction calculates the turnover of the UK Industry to be in excess of £100billion. Therefore if my maths with big numbers is good we fill the equivalent of one hundred thousand homes with CO2 per annum through construction activities alone
What then are the areas we should address in developing a low carb plan to reduce levels and impacts of construction CO2?
passive – getting the foundations right , for example through ensuring all vehicles, plant, cabins and small tools used on site are as energy efficient as is possible, that we start to use renewable energy, eg solar power for small tools where possible and seek to use mains power as early as possible in the contract to avoid use of generators. And of course ensuring all project planning is optimised for minimum energy use.
active – addressing everyday activities to reduce energy and fuels used and hence emissions, through, for example, focus on local procurement to minimise travel and transport, encouraging car sharing, using lean construction to minimise time, reduce energy usage in site accommodation and plant, reduce waste and improve storage.
positive – we can attempt to balance those carbons still arising from construction through education and awareness of people and organisations on projects (so learning can be shared and taken to other projects and offices, also what goes around will come around; your staff and operatives for the next project will be better informed and more likely to save energy.) We can also look at carbon capture via planting of (additional) trees and landscapings
And of course using constructco2 to measure understand and reduce construction carbon.