The UK’s tallest timber office building

Architects Piercy&Co are the designers behind a timber-based redevelopment of the former Holborn Town Hall in London. The site sits on the southeast corner of Gray’s Inn Road and Clerkenwell Road in Camden.

Planning permission has been granted to developers Global Holdings (GHMG UK) to create the UK’s largest full timber frame, net zero carbon office building.

Timber and embodied carbon

Model of 100 Grays Inn Road; image © Piercy&Co

The main building’s structure will be made from a glulam frame with CLT slabs. Its embodied carbon rating is expected to outperform the UK Green Building Council’s ‘Building the Case for Net Zero Office’ baseline target by over 50%: the timber itself sequesters some 2,400tCO2.

“The decision to replace a building is not one we take lightly,” states Harry Bucknall, Piercy&Co Director. “In this instance, detailed whole life carbon studies concluded it was the most environmentally responsible approach.”

Going above and beyond

The use of both timber and circular economy principles for the façade and interiors will exceed Greater London Authority and Camden Council policy targets for sustainability and energy efficiency. The dry nature of the construction facilitates future deconstruction and re-use with minimal wastage. The building is a LETI (Low Energy Transformation Initiative) Pioneer Project – it is seeking to achieve the KPIs of LETI’s Climate Change Design Guide, and is committed monitoring and publishing to in-use data.

Targeting low operational energy

The building is aiming for a NABERS (a building energy efficiency standard) rating of 5.5.

“Achieving net zero carbon requires a ‘whole building’ approach to design,” states Edward Chan, of Max Fordham, who are consultants on the project. “We’ve driven down the building’s operational energy demands by prioritising passive principles and optimising the facade, engineering efficient active systems, and then supplementing through low and zero carbon energy sources.”

This article is taken from issue 4 of Designing Timber magazine