Can your kit cut your carbon footprint?

Is the industry doing enough to reduce site emissions? A delayed Green Construction Board report says voluntary sustainability targets have proven elusive and there is much more to be done. Stephen Cousins looks at the new kit and technologies that could help construction clean up its act.

Over-reliance on dirty diesel generators, old plant with inefficient engines and poorly-insulated site accommodation are all contributing to a CO2-shaped cloud on the industry’s sustainability record.

A forthcoming report from the Green Construction Board – originally due to be published in July – reveals that the industry has failed to meet its self-appointed target of reducing emissions linked to operational site activities by 15% from 2008-2012. The target was originally set by the Strategic Forum as part of the 2008 joint government and industry strategy, the Strategy for Sustainable Construction.

The intention was to cut 750,000 tonnes of CO2 emissions from plant and equipment, site accommodation, and road transport of materials to sites and waste away. Site-related emissions are, of course, only a small slice of the total emissions the industry can influence.

According to Low Carbon Construction, a report from the Cabinet Office Innovation & Growth Team in November 2010, operational energy in completed buildings accounts for 83% of the 300 million tonnes of CO2 emissions in the industry’s control, while manufacturing processes related to construction products account for 15%, product distribution is 1% and site activities another 1%.

Nevertheless, in an era where the industry is being challenged to raise its sustainability game on every front, it looks as though there has been a collective failure to address site-related emissions. The industry points out that there hasn’t been the equivalent of a BREEAM or voluntary accreditation scheme to drive improvement, nor has the issue been touched by the regulatory agenda. And where there are EU regulations – which now force off-road plant manufacturers to fit Stage IIIB low-emission, fuel efficient engines – these have lagged behind the standards set for new cars, trucks and vans.

The Strategic Forum’s original Action Plan to Reduce Carbon, published in 2010, gave a hierarchical hit list of all the elements that make up the operations carbon budget for England (see table). The three biggest offenders – and targets – were site accommodation, where the industry was urged to reduce carbon emissions by 3.9% or 200,000 tonnes a year; efficient use of construction plant (1.7% or 184,000 tonnes) and earlier connection to the grid (0.9% and 150,000 tonnes each year).

Further guidance was included in the government’s Low Carbon Construction Action Plan, published in June 2011, and the Green Construction Board website also points to information published by WRAP and the Low Carbon Trust. However, since these documents were published, the industry hasn’t benefitted from up-to-date data on actual performance, or even a one-stop website to collate all the relevant information.

Green Construction Board member Robert Lambe, managing director of Willmott Dixon Energy Services, told CM: “There are some fundamental, underlying issues with understanding what is happening on sites and what the opportunities are for making energy savings. The data gathered by the Strategic Forum and Arup [when putting together the Action Plan] dates back over six years, and although we are now in a better position in terms of emissions reporting and measurement, there is still a relatively limited sample of data to get a broad picture of the industry.”

Meanwhile, Interserve Construction’s procurement manager Alan Crowe MCIOB believes that public and private sector clients must also bear some responsibility for omitting the targets from their sustainability world view. “Looking at the targets put in place by the Strategic Forum in 2008, what jumps out is that there is very little in terms of client specifications and preliminary requirements for reducing on-site emissions that would help guide main contractors towards specific targets. Reducing emissions has to be driven by clients, but at present it is left largely in the hands of the main contractor and the supply chain. The client will look at BREEAM and the sustainable performance of the product they are buying, but they are not considering site-based operational emissions, which are very high.”

New generation of eco-cabins

Temporary site offices have traditionally been poorly insulated, lacking the building management controls seen in permanent buildings. But even though improving this looks like a clear example of “picking the low hanging fruit,” contractors say that the situation has only recently started to improve, with the arrival of a new generation of site accommodation, such as Garic’s Armadillo Eco Unit.

Interserve Construction’s Crowe says: “In the last six months we have seen greater availability of cabins with good standards, equivalent to an EPC category B rating, at more affordable prices. Buyers like us are becoming more environmentally savvy and wary of kit that isn’t as eco-friendly as manufacturers claim. Where previously, we might have looked for double glazing and insulated doors and shutters, now we do a straight comparison of U-values the way we would with a permanent building. Simple things like automatic door closers can make a huge difference.”

However, he says the industry still lacks a set of environmental standards for on-site accommodation to help guide buying decisions. More efficient use of construction plant was the second key area in the Action Plan, targeted to save around 84,000 tonnes of CO2 or £19m in fuel costs a year.

But Dan Thompson, heavy plant leader for Laing O’Rourke-owned hire company Select Plant, acknowledges that manufacturers only raised their game on fuel-efficient kit in 2013, with the arrival of tighter EU emissions standards for non-road mobile machinery (NRMM), including construction wheel loaders, bulldozers, non-road trucks, excavators and forklift trucks. The tougher Stage IIIB standard was enforced for new plant with engines between 56 and 560kW manufactured since last summer and is the first time the standard for emissions – including pollutants as well as CO2 – had been raised since 2006.

“The engines burn hotter so there are less emissions, they work quieter and there is a 20-25% saving in fuel consumption. It’s the biggest step forward we’ve seen,” says Thompson.

In some categories, such as excavators, dumpers, concrete pumps and cranes, as much as 40-50% of Select’s fleet is now Stage IIIB compliant. “Because we were working on Crossrail [which enforced the Stage IIIB standard for its contractors since 2012] we had to go out and purchase kit of that specification as soon as we could. Now we can foresee it becoming a requirement of other clients too.”

That is already happening in London, where mayor Boris Johnson is to ban all construction plant in the “central activity zone” that doesn’t comply with Stage IIIB from September 2015 – in effect phasing out older, non-compliant plant. The rest of the capital will have to meet the less stringent Stage IIIA.