New mass timber teaching building for Notting Hill and Ealing Girl’s School redevelopment project.
Eckersley O’Callaghan has been involved as the structural engineer from the concept design stage providing full structural design and timber expertise to assist in the tendering process.
The building consists of a two and three storey teaching facility comprising an almost-entirely mass timber frame. The building functions include a centralised space & foyer, 14 new classrooms, a science lab, specialised facilities for art, science, ICT and a new enlarged library.
The mass timber solution consists of a primary frame of glulam columns and beams providing internal supports, together with some isolated Cross-Laminated Timber (CLT) walls used for lateral stability. To mitigate the risk of timber being exposed to high humidity, steel columns have been used to form the external colonnade. The timber frame is to be architecturally expressed in some locations which has necessitated careful detailing of the visible connections, particularly in the lattice roof of the entrance foyer. Another key design aspect was the long term movement of the perimeter glulam beams supporting the brick facade, which needed to meet a more stringent deflection criteria.
The saw tooth roof selected for its reference to the local area and its character, uses three-ply spruce panels supported on regular glulam rafters spanning between the second floor and the ridge beam, which is supported by pre-fabricated triangulated glulam A-frames.
Our design for the long-spanning floors, just under 8m in typical classrooms, use pre-fabricated CLT ribbed panels made of glulam beams and CLT topping slab. This solution compared against a typical solution of a solid CLT plank option has reduced the timber volume by 60% enhancing the sustainability attributes and achievements of this project.
The building, which is situated on a brownfield site, uses piled foundations to transfer load past the ground level which has negated the need to excavate the soil.