The former Bethnal Green Mission Church was an inaccessible 1950s building with severe maintenance issues, which was demolished and replaced with a new mixed-use development with a church at its heart.
The new building needed to increase useable space for the client while adhering to planning conditions which stipulated the new seven-storey building could not exceed the height of the Grade II* listed Museum of Childhood opposite.
Comparisons between the use of concrete and timber showed that a fully concrete structure would reduce floor to ceiling heights due to the increased depth of the transfer structures.
The building is a hybrid Cross-Laminated Timber (CLT) / concrete structure that makes use of an existing basement, and so using a lightweight material such as CLT for the upper floors was essential. The CLT reduces embodied CO2 and building mass and provides high levels of air tightness. An added benefit of this approach removed the necessity for deep piles as a raft foundation was viable, saving on cost and programme. This building is an excellent example of identifying the advantages different materials offer and getting the most from them.
The double height space to the church and its coffered ceiling is the main feature of the new Bethnal Green Mission Church. The expressed ribs create a diagonal grid to reference the vaults of traditional churches. The structural design of the ribs, spanning 11.0m, needed to consider the intersection point of two ribs resulting in a shallower depth to the tension reinforcement. The main challenges with forming a diagonal grid was creating a formwork design which dealt with the acute angles while leaving a blemish free exposed concrete. This was achieved through trial panels and iterations of formwork design to achieve an excellent quality finish.
The building has enabled the church to continue and extend their local services including youth and interfaith groups, and the inclusion of a cafe and the rental of offices to charities give the church an income stream ensuring its long-term financial viability.