In partnership with Leeds City Council, Interserve, the international support services and construction group, is soon to deliver another Leeds school certified to Passivhaus building standards. Swillington Primary School is being delivered through the Leeds Local Education Partnership, of which the Interserve-led consortium ‘Environments for Learning’ is a partner. The project is nearing completion, with May 2012 being targeted for handover. The timber frame construction is being built on a reinforced concrete slab. The whole building is surrounded by 250mm insulation and is partly rendered and partly timber clad. The roof is being clad in Falzinc, which incorporates an aluminium core with a weathered zinc surface.
The 1500 sq.m. structure has been designed by Passivhaus specialist architects, Architype, for Leeds City Council. Once completed, the new school will use up to 80 per cent less energy than a conventionally built equivalent structure, thanks mainly to superior air tightness and high levels of insulation. Indeed, the rigid urethane insulation used under the slab has been precision-cut using a heat-cutter, so extreme are the tolerances involved. The building’s timber frame, featuring Warmcel cellulose fibre thermal insulation, provides a thermal bridge-free construction, thereby helping to eliminate heat loss.
Mostly single storey, the school features composite triple glazed windows in aluminium and timber, which are themselves Passivhaus certified.
Throughout the construction process, Interserve is providing regular, careful photographic evidence to WARM, the low energy building practice and a certifier for the Passivhaus Institute, in order to prove the Passivhaus credentials of the build, ready for its anticipated certification.
An interesting feature of the build is its timber frame element. New World Timber Frame has taken just 11 weeks to prepare off-site all of the required timber frame structures with their requisite insulated panels, which are simply craned into position on-site. Working off-site in this way helps to optimise quality control; it keeps site costs down and eases work scheduling through the dependability of a factory environment, which is of course not weather-dependent.
The second Passivhaus school in Leeds that Interserve is currently constructing is Richmond Hill School, which is scheduled for completion this autumn.
