Basements & underground structures best practices

The Ground Engineering Basements and Underground Structures event returned to London in March 2026.

We listened to interesting presentations about the Fifty Fenchurch Street project, CERN’s future circular collider and The Palace of Westminster Marine Ground Investigation works, before a panel of leading contractors joined Duncan Moore, editor of Ground Engineering, on stage.

With a title, ‘Deep excavation project best practice: early collaboration in successful basement construction’, the panel included Kevin Ryall, our Senior Bid Manager, James Simpson, Construction Engineering Director, McGee, Claire Lepoutre, Technical Services Director, Skanska, Dr James Cox, Principal Geotechnical Engineer, Kier, Dimitrios Tziogas-Papandreou, Head of Temporary Works, Multiplex and Martin Stanley, Divisional Director South, Bachy Solentache.

With project build programmes becoming more condensed and clients wanting projects delivered faster for less, the panel discussed how contractors achieve the best temporary works design, sequencing and installation plans, to deliver a more efficient and safer project. The group set out to ensure the audience would understand the blockers and drivers of early collaboration in basement construction, how to achieve value engineering in temporary works, balancing a trio of cost, quality and time, and also touched on sustainability demands.
Here’s our highlights from the panel discussion…

On early collaboration.

Dimitrios said “It’s important to explain the parameters to the client and ask about constraints early on, when there is more positive influence on outcomes and costs. We can then take them through the journey with specialists to improve buildability.”

Martin said: “The Gateway II process is improving collaboration. Clients want more flexibility commercially but at some point, parties do need to be locked in to build the best solution.”

Kevin said: “It’s difficult to quantify early collaboration but the further down the programme and design and technical pathway can impact the project parameters and cost immensely. The UK does well but we should collaborate earlier with specialists to create a plan that runs right through a programme.”

James Simpson said: “It’s common to be brought in at RIBA stage 3 or 4, but if you offshoot those then opportunity to improve the scheme is reduced. Building a basement is a very complicated activity with engineering judgement, expertise and process. We work with consulting engineers and contractors and in order to deliver client value, the earlier the better.”

What does good look like in basement construction?

James Cox said: “There is a push to be more sustainable and when we’re involved early on, we can integrate the Temporary and Permanent Works structures. Requirements have to be solutioned to address both elements. Clients are pushing sustainability and it’s up to us to bring lots of proof and examples to demonstrate it can be done.”

Dimitrios said: “Sometimes we find there is misalignment between project objectives and the milestones that the client has set. Those milestones may be driven by project financing rather than feasible programme milestones. The value is achieved by jump starting the super structure while the basement is in progress.”

Claire said: “The client’s contract needs to set realistic objectives and the main contractor then sets the tone for honest communication with specialists, reducing risk and improving quality. The biggest gap is honest communication.”

James Simpson said: “Basement projects are the poster child for the rest of construction industry. Geotechnical engineering is rooted in translating theoretical analysis into practical implementation in order to achieve sustainable solutions.”

What else can we improve?

James Cox said: “Clients probably don’t realise all the potential methods in basement construction. That means we all need to demonstrate understanding and knowledge, working with specialist contractors, to show where improved methods and sequencing can change the outcome. Doing so can dramatically reduce risk and complexity.”

Interested to work with Conquip in the pre-construction phase of projects? Contact us at twengineering@cqegroup.com.