• Client: Birkbeck, University of London
• Architect: Penoyre & Prasad
• Photographer: Timothy Soar
• Completion: 2021
• Value: £19m
• Size: 1807m²
• Expertise: Structures

Situated within a sensitive heritage context on the outskirts of London’s Bloomsbury area, 373 Euston Road, formerly known as Cambridge House, is a bold new 1,807m² teaching and learning space for the University of London’s Birkbeck College designed by Penoyre & Prasad.

Having now undergone a major refurbishment and extension, 373 Euston Road is transformed into a striking six-storey building that accommodates a café and learning hub for students on the ground floor and basement, teaching and learning spaces on the upper floors, and a large modern lecture theatre in the new rooftop extension.

In order to extend the building upwards, extensive analysis of the existing building was carried out to ascertain its structural capacity, and although some strengthening works were necessary to allow for the additional loading, the focus was on proposing a lightweight extension that would minimise strengthening where possible.

The lightweight, copper standing seam extension is created using a steel transfer structure at the 4th floor which continues up to the lecture theatre above. CLT panels form the floors and load bearing CLT panels form the internal and external walls. The seating area in the lecture theatre follows the shape of the structure – meaning that no secondary structure was needed to support the seating – and is left exposed, with horizontal CLT panels spanning in between the supporting glulam beams.

By renovating and extending this 1920s former car showroom, the embodied carbon of the development was dramatically reduced. The use of exposed CLT and glulam for much of the new structure helped to reduce the carbon cost and the amount of finishes required.

The estimated embodied carbon for the scheme is 353 kgCO2e/m2, with the structure comprising 189 kgCO2e/m2 of this. This value is well below the RIBA 2020 target of 800 kgCO2e/m2 and even the 2030 target of 500 kgCO2e/m2 without taking into account the sequestered carbon.

Shortlisted at 2021 Structural Awards for Structural Transformation, and Minimal Structural Intervention and hailed by the judge's:

The refurbishment and extension of this 100-year-old building was enabled through skilful structural engineering.

The choice to extend the building carefully balanced the client’s ambitions to minimise capital expenditure and development risk, and increase the building’s floor area, within the structural capacity of the existing building, without significant environmental impact. 

Detailed structural analysis was used to ascertain the building’s existing structural capacity and the design of an innovative lightweight extension increased the floor area by nearly 30% and at a cost far less than estimated for rebuild.