The completion of a new activity hall at Haydon School, Pinner marks the 10th year of Nick Baker Architect’s involvement in the development of Haydon School, and the penultimate phase of a Masterplan and an initial Strategic Development Plan - developed a decade ago. Located in an infill site with a 3m level change between adjacent buildings, the hall is raised to provide valuable covered play area below and panoramic views over adjacent playing fields. Corridors wrap around the South and West of the hall, linking two separate wings of the school for the first time. This, alongside a new passenger lift to the West of the hall, greatly improves efficiency of circulation and provides covered access for wheelchair users. The hall and corridors are passively ventilated using ventilation towers, and extensive use of polycarbonate cladding provides diffuse natural light to deep within the hall whilst maintaining high thermal performance. A tactile and utilitarian approach was taken to materiality in response to strict budgetary constraints. Exposed blockwork and in-situ concrete are used extensively within the corridors and exposed plywood forms the rebound wall within the hall. Strategic Development Plans Over the last decade Nick Baker Architects have developed specialist skills in master planning schools. Our approach is underlined by the principal that the course of an expansion for a school should be considered as an opportunity not just to provide additional accommodation, but also address fundamental issues relating to existing anomalies in the composition and efficiencies of school buildings.