Alex Brock, Senior Pre-Construction Manager at B&K Hybrid Solutions (BKHS) builds a case for hybrid timber construction and explores what a growing diversity of projects says about the direction of this important market.
The construction industry continues to face significant pressures. Rising material costs, changing regulations and tighter project budgets have challenged procurement decisions across the industry, while expectations around carbon reduction and programme certainty continue to increase. Hybrid timber construction has established itself as a solution and is now being delivered across a wider range of building types than ever before. Once associated primarily with offices and education projects, engineered timber – combined with structural steelwork and other materials – is now being specified for retail, residential, industrial, infrastructure and more.
An exemplar of commercial timber construction
The recently completed Metropolis development at 242 Marylebone Road demonstrates how hybrid timber construction can unlock ambitious refurbishment schemes without compromising on sustainability or architectural ambition.
A transformation of the former Woolworths headquarters, originally designed by Richard Seifert & Partners in 1959, the project added seven new storeys while retaining 93% of the original structure, increasing total floor area by 40% to approximately 174,000sq ft. BKHS delivered 1,500m3 of predominantly exposed cross laminated timber (CLT) alongside 500 tonnes of structural steelwork, connecting the new extension to the retained concrete frame through detailed ferroscanning and more than 100 resin anchors and fixings. The steelwork, fabricated in-house by BKHS, worked in combination with the CLT to achieve the long spans and structural performance that CLT alone could not have delivered, while keeping the overall frame lightweight enough to avoid costly foundation strengthening. The sustainability credentials are significant: retaining 93% of the original fabric saved over 4,500 tonnes of CO₂e, while the CLT sequestered a further 1,113 tonnes within the structure. Metropolis has since become one of very few refurbishment schemes in the UK to achieve BREEAM Outstanding, alongside an EPC A rating and net zero carbon in operation.
Frederic Schwass, CDO of General Projects, commented: “BKHS brought a highly co-ordinated offsite approach to the Metropolis extension, using timber to its best use across the project. Their hybrid CLT solution allowed us to deliver a lightweight vertical extension with exceptional dimensional accuracy, while working within the constraints of the retained 1950s structure and supporting our wider low-carbon ambitions.”
Demonstrating scale
Fife College’s Dunfermline Learning Campus illustrates what hybrid timber construction can achieve at scale. As Scotland’s first net zero-ready tertiary education campus, the project marked the UK’s first combination of CLT and Peikko DELTABEAMR, across a 20,000m2 development. Appointed by Balfour Beatty, BKHS delivered 1,879m3 of CLT, 1,240 tonnes of in-house fabricated structural steelwork, and 337 tonnes of DELTABEAMR, completing the hybrid structural package within 26 weeks while working adjacent to two operational schools.
The completed teaching block achieved an independently verified embodied carbon footprint of 560kg CO₂e/m2 against a target of 650kg CO₂e/m2, representing around a 20% reduction compared with an equivalent concrete solution. The project has since been described by Fife College’s Principal as: “the new minimum standard for all future public builds in Scotland.”
Growing applications
The variety of projects now specifying hybrid solutions tells its own story. In the retail sector, Tesco’s flagship Low Carbon Concept Store in Harrogate represents a significant evolution. Having historically specified structural timber only in customer facing areas, the Harrogate store sees 299m3 of exposed glulam incorporated throughout both the front and back-of-house for the first time, reflecting the retailer’s confidence in the material. Having previously delivered hybrid timber stores for Tesco, BKHS’ return to the sector resulted in an 81% carbon reduction compared with a full steel alternative. The Harrogate store is now intended to serve as the blueprint for future developments across the Tesco estate.
Elsewhere, 38 Berkeley Square has become the first commercial CLT building to achieve SWECO Building Control compliance since changes to UK fire regulations in 2021 – early engagement of specialists such as BKHS under a PCSA was key. The first new office building constructed on the historic Mayfair square for more than two decades, the project combines 1,614m3 of CLT with approximately 1,000 tonnes of structural steelwork to achieve generous 2.8m floor-to-ceiling heights with visual timber soffits, while the lightweight hybrid frame reduced concrete consumption by around 50%.
In the residential sector, the Univ North development at University College Oxford demonstrates the advantages of timber for constrained urban sites. Across four accommodation blocks, BKHS delivered 866m3 of CLT and glulam, reducing site deliveries by up to 80%.
Early engagement of specialist subcontractors is a running theme throughout these projects. BKHS’ ability to deliver the full design and build package, including in-house steelwork manufacture, removes interface risks and gives clients a single point of responsibility from concept through to completion. As interest continues to grow in other sectors such as infrastructure, industrial developments and data centres – as seen at Gatwick Airport’s Pier 6 Extension and Cheadle Eco Park – navigating each new application’s technical demands requires the kind of specialist experience that only comes from delivering complex hybrid projects across multiple sectors. Now, hybrid timber construction is a proven structural solution for clients and developers looking to balance genuine carbon reduction with programme and budget demands.
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