National Highways has announced Skanska as the preferred bidder for the Kent Roads contract on the £9bn Lower Thames Crossing (LTC) project.
However, it has confirmed that a 30% cut in projected carbon emission under the £450m contract brings emissions to the level it has already stated to be current best practice.
The government-owned company has designated the proposed road tunnel connecting Kent and Essex as a Pathfinder project for carbon neutral construction and described it as the first major infrastructure project in the UK to use its main procurement process to seek the lowest carbon construction available in the market.
However, as Highways has reported, previous claims of carbon reductions prior to the project’s applications for a development consent order (DCO) have involved comparison against outdated material specifications, while a claim that a previous contract involved significant carbon reductions also ran into accusations of greenwashing.
The £450m Kent Roads contract will deliver almost four miles of new road and structures on the southern part of the route that connects the A2/M2 to the tunnel approach.
Despite claiming to be using procurement processes to cut construction emissions, National Highways has not stated that Skanska offered the lowest emissions of the four bidders, who also included a joint venture comprising BAM Nuttall, Ferrovial and VINCI Construction Grands Projects; Costain Limited; and another joint venture comprising Kier Highways and Eiffage Génie Civil.
The government-owned company said that it had asked for a minimum of 30% reduction across the project and that the bid from Skanska proposes an even more challenging limit. However, it confirmed that the 30% reduction brings the scheme into line with the 1.763 million tonnes of CO2 equivalent outlined in the DCO application.
The company's Carbon and Energy Management Plan under the DCO states that it considers the figure of 1.763 million tonnes to represent current best practice for low carbon construction, adding that it 'is focused on moving beyond current best practice and will pay a financial incentive for every tonne of carbon reduced below this current best practice level'.
It has claimed since 2020 to have made a one-third cut in construction emissions and clarified that figure cited in the DCO application represents a cut against a ‘counterfactual’ baseline. However, it subsequently admitted that this involved, for example, comparing the use of significant amounts of ground granulated blast-furnace slag (GGBS) – a commonly used low carbon cement replacement – against ‘zero’ GGBS in the baseline.
A spokesperson said: 'At this stage, whilst we are finalising contracts with our Delivery Partners, we will not disclose any further information about the carbon baselines that will be used in those contracts.'
However, the company said it will support Skanska in its 'ambition' to go further 'through a low carbon design approach, developed with Mott McDonald, and close working with its supply chain to ‘champion’ new and innovative materials and technologies during construction.
Katharina Ferguson, Lower Thames Crossing procurement director, said: ‘Skanska has a track record of providing innovative low carbon solutions to projects, and leaving a genuine legacy of skills and innovation in the local community.'
‘We look forward to working together to deliver this desperately needed piece of new infrastructure in a way that pushes the boundaries in low-carbon construction and social value.'
The Kent Roads contract is the second of three major National Highways contracts that will deliver the Lower Thames Crossing.
In January, the larger Roads North of the Thames contract was awarded to Balfour Beatty. In that announcement, National Highways made no reference to having used the procurement process to lower construction carbon, other than to state that Balfour Beatty ‘share our commitment to driving carbon out of construction’.
Balfour Beatty said it ‘will utilise modular construction techniques to build the structures offsite in a controlled factory environment, significantly reducing carbon emissions by minimising the number of lorry movements and material deliveries to and from site’.
However, when asked to quantify the carbon saving this would achieve, the firm said it would explore techniques that support the project’s low carbon targets during the 18-month detailed design and pre-construction planning phase.
National Highway has said that a separate contract for the Tunnels and Approaches is expected to be awarded later this year.
According to the Carbon and Energy Management Plan the work to build the two tunnels accounts for 54% of total construction emissions, the Roads North of the Thames element accounts for 34% and Kent Roads 12%.
