Keltbray Project Showcase at the IBM Building

Keltbray, the UK’s leading specialist in construction engineering and infrastructure services, are proud to present our work on the once IBM Building at 76 Upper Ground on behalf of Stanhope PLC.

76 Upper Ground, a historic landmark on London’s Southbank, designed by Sir Denys Lasdun and completed in 1983, proudly stands alongside the National Theatre, achieving Grade II listing status in 2020.

Scope of works

Keltbray were initially awarded the enabling works contract to prepare the building for follow-on permanent works. The enabling works consisted of soft strip, deconstruction of the listed pre-cast cladding, partial demolition, hydro demolition to the exposed slab edges, and concrete cleaning for internal walls and columns.

Additionally, our in-house design consultancy Wentworth House Partnership (WHP), designed and installed temporary works to ensure the building’s stability after the central core’s removal. Special attention was given to preserving the appearance of columns, with unique and dynamic collar designs used to attach temporary bracings where columns were exposed in the final scheme.

Variations of temporary structures designed by WHP and installed on site to support core structures

Follow-on piling and substructure works were awarded, with significant programme benefits achieved by prioritising the ground floor & basement strip out to allow the mini piling to take place. The scheme involved over 300nr new mini piles to supplement the existing foundations. The works also involved connection of the new pile caps into the existing and additional drainage cut into the existing ground & basement slabs.

In February 2023, we were awarded the follow-on superstructure FRC works for constructing the new core and slab extensions directly through Multiplex.

Concept Drawing of 76 Upper Ground development

Salvaging and retaining London’s heritage

The works at 76 Upper Ground embodied circularity within the planning stages, whilst also following Stanhope’s specifications to dismantle and retain the iconic heritage concrete façades and exterior panels. We also explored opportunities to salvage and retain other elements of the building.

Keltbray’s core purpose, to redefine the way sustainable development is delivered, is centred on viewing everything we demolish as a potential asset for reuse. We define sustainability in demolition by maximizing the value of arising materials for as long as possible.

Circular economy achievements for the project so far include:

• 27,360 Raised access floor tiles equating to 169,632kgCO2e emissions saved*
• 82 listed façade panels (weighing an average of 6 tonnes per unit) equating to 88,068 kgCO2e “
• 95 tonnes of paving blocks equating to 25,485 kgCO2e “
• 71 tonnes of bricks equating to 15,123 kgCO2e “

*Notes on emissions savings methodology can be found at the end of this article

Keltbray has also organised the reinstallation of 40 tonnes of dismantled steel for the new structure at 76 Upper Ground, with material sourced from another Keltbray demolition project in the London area. This will reduce the embodied carbon of this structural component from 577kg to 47kg per tonne equating to a total savings of 21 tCO2e.

Following Stanhope’s directive to reclaim the historical structure, Keltbray identified extensive opportunities for reuse throughout the entire project.

Our standard practice for demolition works includes a pre-demolition audit to identify potential materials and components for reuse before works are undertaken. Once works commence Keltbray utilise our in-house reporting system to gather data, to aid our decision-making process, identify new oppurtunities for efficiencies and adds a layer of transparency between us and our clients.

Material Reporting

Powered by Microsoft’s PowerBI, our newly upgraded reporting system allows for precise tracking and analysis, incorporating industry-standard carbon factors to determine carbon emissions for each component.

Screenshot of PowerBI dashboard showing material reporting capability for IBM Building

Energy reporting

All project mains and mains equipment such as cranes and pumps are powered by mains electricity; only remote equipment is powered by fuel and is closely monitored, using the latest in telematic technology to monitor and identify inefficiencies on projects, playing a crucial role in reducing carbon emissions.

Our utilities team assess every site to ensure the most efficient utilities connection and disconnection requirements. Our teams’ efficiencies are evident from the savings performance present in 2022.

Revolutionising Construction: Keltbray Achieves 100% Electrification at Heathrow Cargo Tunnels

Screenshot of PowerBI dashboard showing energy reporting capability for IBM Building

Logistics, Challenges and Stakeholder Engagement

The building’s Grade II listed status required close collaboration with the heritage architect, who also formed part of the client’s consultant team. As such all methodologies must be agreed with them and where we are cleaning and repairing the existing structure, benchmarks have been produced to ensure the desired standards are being met.

Additionally, we maintained a strong partnership with UKPN to protect their assets, a basement substation, whilst ensuring 24/7 access.

The National Theatre (NT) was the Clients single biggest risk for the project. Provisions were agreed between the Client and the NT that contained restrictions on working hours and noise limits with financial penalties linked to the severity of the breach.

During the pre-start phase we liaised with the NT and established the trust that saw their continued and uninterrupted operations as the main driver for our delivery of the works. Our sequencing and methodology were influenced to ensure that the restrictions were adhered to. For example, the NT has consolidated all matinee performances to one afternoon per week, our programme ensured that no noisy works are undertaken at those time.

Another third-party stakeholder linked to the project is the Coin Street Residents Group, a collection of residents based to the south of the project whose purpose is to ensure that developers and contractors working within the area listen to their concerns in order to minimise the impact of works on those who live in the surrounding area. Through successful collaboration, we have ensured a seamless project without any reported issues.

Conclusion: A Blueprint for Sustainable Excellence

The project at 76 Upper Ground stands as a blueprint for sustainable excellence in the construction industry. Our commitment to preserving heritage, implementing circular economy principles, and maintaining rigorous standards has transformed a historic landmark into a symbol of sustainability.

*Emissions Savings Methodology

Emissions equivalents are calculated inhouse, through reported quantities of materials against carbon factors issued as part of our Environmental Product Declarations for key building materials.

Carbon factors associated describe the Global Warming Potential (GWP) specific to each material. GWP considers the supply of raw materials as well as the transport and manufacturing of goods when defining kgCO2e associated with materials.

ENDS