Plot H1 is the final plot of Lendlease’s Elephant Park masterplan, located prominently, adjacent to the train station and the new Elephant & Castle Town Centre development. Providing over 500,000 sqft of office space over 18 storeys, with a range of large floor plates, it brings the potential for much employment from small, medium and large enterprises to an area undergoing regeneration.
From the outset, the goal was to use visual mass timber, both offering reduced embodied carbon compared to typical concrete and steel frame solutions, and a desirable ‘timberness’ quality to the spaces within the building. It was also considered essential to provide column grids of 9.0m to deliver high flexibility of fit-out and to compete well with concrete or steel office products in the market.
In response, we developed a hybrid frame using CLT planks and steel cellular beams, enabling a shorter storey height than a full mass-timber frame, and providing a higher degree of flexibility around MEP services in the ceiling compared to glulam. Steel columns maximise the floor area compared to concrete or timber columns, and the reinforced concrete core provides high fire-resistance solution for escape and lifting. This true hybrid exploits the best benefits of each material while meeting an aspirational brief to deliver uniquely attractive office spaces.
The project is much larger than UK office projects to date involving mass timber. Consequently, significant engagement with the mass timber supply chain has been required from the very start, to ensure availability, reliability of volume of supply, and optimisation of mass timber elements to minimise wastage.
Such a significant office building formed of unconventional construction requires a bespoke approach to Building Regulations. From a very early stage we engaged with expert fire consultants OFR, to develop a robust and efficient solution to the problem of using combustible structural materials. The fire condition governs the CLT plank size and specification.
Through combining the best advantages of mass timber, steel and reinforced concrete, and through careful specification of each, the embodied carbon of the structural frame is low, allowing the building to meet ambitious targets.
In planning stage design, In the construction phase of its life (A1-A4) the structure demands 272 kg CO2e/m2 of embodied carbon, accounting for 58 kg CO2e/m2 GIA of carbon stored in the CLT elements.
• 18 storeys + basement
• ~65,000m2 GIA
• ~45,000m2 NIA
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