NDY’s Chris Nunn

18 July 2013 — London’s Crossrail has an ambitious sustainability strategy and has used life cycle assessment to make green building choices, Norman Disney & Young sustainability leader Chris Nunn told the 8th Life Cycle Conference this week.

Crossrail is a new high frequency, high capacity railway in London which includes six underground stations beneath the existing tube network, and will increase London’s rail capacity by 10 per cent, see 200 million passengers a year and contribute to a reduction of 500 million kilometres of car journeys annually.

Overland trains west to Heathrow will connect the airport to the centre of London and out East to Shenfield, enabling a far greater number of people to get to the centre of London within 45 minutes.

Construction is currently underway and the stations will open in 2018.

The environmental impact of construction has been a focal area for the “really futuristic, aspirational” project, says Nunn. He worked on the six underground stations at Paddington, Bond Street, Tottenham Court Road, Farringdon, Liverpool Street and Whitechapel.

An artist’s impression of Tottenham Court Road station

His role as sustainability leader for architectural components team, which handled the specifications for the fitout of the underground stations, enabled the team to incorporate environmental data on materials and have a tangible effect on what was selected for the £16 billion infrastructure project.

The design team at the early stage were looking at choices between floors, floor tiling, walling, ceiling panels, fixtures, fitting, lifts, escalators, cable management systems, communications, lighting strategy, signage and public artwork.

Nunn’s team provided them with sustainability input to assist in choosing the right products, looking at eight product categories and 29 material types.

Nunn said the key driver was that Crossrail had fairly ambitious sustainability targets, with a sustainability strategy and a series of indicators that included carbon footprinting, materials analysis and BREEAM compliance.

The starting point of the project, and many projects, was a lack of awareness by architects and specifiers of comparative environmental attributes of products being considered, said Nunn, as well as a lack of relevant product declaration information from suppliers.

“None had an environmental product declaration consistently reporting the same metrics, and none had done an LCA on the products being considered, which is a bit unusual for a £16 billion infrastructure project,” he said.

A building information model of Tottenham Court Road Station

Nunn’s team developed an online sustainability questionnaire to gather information from suppliers to compare across products, collated available data on products and used a scoring matrix to evaluate options and collate suppliers’ responses. The results were reported to the design team using a “design log”, which became the basis for decision making and communication to the client.

Information was communicated through a traffic light system of green, amber and red – if it was red it could be vetoed.

“The goal of the analysis was to inform the decision making process and make explicit these environmental issues and trade-offs inherent in deciding between the different types of materials,” Nunn said.

They gathered information on embodied carbon emissions, recycled content, wastage rates, service life information, maintenance implications, operational carbon emissions, toxicity, volatile organic compounds and end-of-life disposal options.

Sustainability was just one of seven criteria for the materials selection, Nunn said, however it was actually used as a key factor in the final product selection.

“It’s usually a bit of an after-the-event look-up,” he said, with typical projects just doing business as usual then looking into sustainability after the fact.

“That’s actually the reality of the process people go through.”

The key outcome, Nunn said, was that environmental information was made more transparent, and that it was fed into decision making.

“We did a lot of training and engagement with the architects and engineers, and I think they came out knowing a lot more about the products that they typically specify,” he said.