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Detail

Swimming Pool for a school in Beaconsfield
01/11/14

Text: Christian Schittich

Alfriston School, a special-needs secondary school, is located outside London, on the edge of a residential neighbourhood.

The existing school building is organised as line­ar cluster, running from the street to the veg­etation in the rear, with small-scale gabled roofs of varying orientation. To its north a new swimming pool structure with expres­sive crown docks onto a sports hall with steep pitched roofs. Dark-grey rendered wall and plinth surfaces, and, in the longitudinal elevation, corresponding sloping roofs tie this new sports complex together. Mature trees provide a screen to the schoolyard.

The roof geometry, which consists of serial and interlocking pitched-roof elements, is a reinterpretation of the roofs present nearby. Inside, the sculptural form creates a ceiling with an undulating roofscape. The ceiling al­so serves an acoustic purpose: it reduces the noise level -thereby fulfilling an impor­tant requirement from the client’s brief. A band of glass just one metre in height ac­centuates the roof. This type of connection to the outdoors also provides the children a measure of privacy. Moreover, the glazed ribbon affords them a panoramic view of the surroundings as they jump in the pool.

The roof is made up of 26 triangular wood pan­els, which, once they have been mounted, constitute a stiff roof structure. The fabrica­tion, construction sequence, and transport, however, all posed challenges. To guaran­tee precise execution and high-quality sur­faces, the architects decided to have the panels produced off site. There was only one exception: due to its size, it was neces­sary to construct one gable element on site. Through the use of 30 modelling, in combi­nation with 5-axis CNC milling, it was possi­ble to secure a high degree of fitting accura­cy with small dimensional tolerances; mock­-ups were employed to test individual joints. The load-bearing elements were equipped with a weathertight membrane so that the roofing could be installed right after mount­ing was completed. The coatings on the in­ner surfaces were applied at the woodwork­ing shop. Thus, assembly took just four weeks, and no scaffolding was required.

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