Flora and fora
Pre-fab timber meant low costs and a speedy build at Sheppard Robson’s Hertzberger-inspired Waingels College
Sheppard Robson’s Waingels College on the outskirts of Reading is virtually all wood. Yet sustainable design did not drive the decision to build a timber school.
Delivered through the Building Schools for the Future One School Pathfinder programme, under which local authorities are given the opportunity to completely redevelop one (and one only) secondary school in their area, the multi-phase project largely replaces an existing secondary school on the same site.
While both client and project team viewed timber as sympathetic to the school’s location at the edge of the green belt, the deciding factor was the operational flexibility offered by prefabrication. ‘We looked at a full decant, but that would have cost £2.5 million and we preferred to put that money into the building itself.
Prefabrication enabled us to build cheek by jowl with the existing school,’ says Sheppard Robson design director Lee Bennett.
Waingels’ volumes create a cheerful environment, both indoors and out
The school is organised in four blocks around a central outdoor court, bucking the ubiquitous trend for an enclosed central atrium in favour of offering students a breath of fresh air between lessons.
A palette of softwood cladding and coloured render wraps four buildings – an entrance building housing the main hall and library and three specialist classroom buildings – which are almost identical in massing and differentiated by subtly coloured renders representing the four seasons. Despite value engineering on the landscaping, the result is a well-proportioned and uplifting collective outdoor space for the entire school.
The brief for the teaching spaces – developed with client design adviser Paul Fletcher – was adventuresome, even though the project’s initial environmental aspirations were less so. Teachers were seen as role models and mentors, not disciplinarians, and this called for buildings that would enable passive supervision and blur the distinction between teaching and learning. The architects responded by minimising cellular classrooms and maximising open learning areas organised around central fora, Hertzberger-inspired stepped auditoria, which can each accommodate up to 250 students.
While it is a brave move, the long-term flexibility of these stepped spaces is questionable. They could prove a straightjacket over time, compared with similarly-sized halls on a single level. Their appeal is not helped by the combination of carpeted treads, timber risers and aluminium nosings, which are a significant departure from Hertzberger’s all-timber Apollo School stairs in Amsterdam. Nonetheless, the forum spaces provide useful, strong orientation within the teaching blocks.
The fora are surrounded by highly flexible open learning areas, made possible by the use of long-span glulam structure. The result is deep-plan buildings, which create challenges for daylight penetration, natural ventilation and acoustics. With the input of services engineer Skelly & Couch, a robust design was developed which uses timber’s light weight. Butterfly roofs over tall clerestory-lit volumes – approximately a storey and a half – enable sufficient air changes to naturally ventilate the teaching areas and control potential overheating.
Mark Skelly, of Skelly & Couch, explains that school buildings primarily require cooling and that, as soon as the exterior temperature rises above 3°C, the demand for cooling kicks in. Without thermal mass to lower radiant temperature of the spaces, extra-tall volumes – 5.5m high at the perimeter – allow heat to be quickly removed from the occupied zone. ‘The rooms are, overall, hotter than a thermally massive building, but much of the heat is at high level, where no one will notice it,’ Skelly explains.
Banks of panoramic windows offer views to trees. The effect is one of airiness and connection to the outdoors, even though the glazing ratio is a surprisingly low 25 per cent to control solar gain. The tall spaces also deliver extensive surface area for acoustic control. Attractive perforated timber panels are integrated into the ceiling cassettes, eliminating the need for baffles.
The only environmental requirement of the design brief was to meet the government’s 2007 Low Carbon Schools requirement for a 60 per cent carbon emissions reduction over Part L 2002. Waingels is one of the first schools required to do so. This was achieved by using biomass boilers, sized to meet the 60 per cent reduction and anticipated to meet 90 per cent of the annual heating load. ‘We only look at biomass if there is a robust supply chain,’ says Skelly.
It turned out that a Waingels parent was managing director of a local wood recycling company that sources timber waste from construction sites and landscape contractors. A BREEAM ‘Very Good’ rating was considered adequate. Credits were lost on transport, due to the location of the site and the extra investment required to achieve an ‘Excellent’ rating was deemed better spent elsewhere, such as on higher-spec glazing. Unfortunately, no monitoring is planned to measure how the building will actually perform.
Sheppard Robson is developing an expertise with timber buildings. Its portfolio includes two schools in Norwich, the Oasis Academy in Croydon and the Lancaster Institute for the Contemporary Arts (AJ 27.10.11). So what is the verdict on this school, in which timber is omnipresent? Eurban, the project’s timber designer and supplier of engineered board, champions timber’s familiar qualities as a renewable material.
The flexibility of the teaching spaces is a plus, yet one can’t help but wonder about the longevity of the softwood exterior, particularly the brise-soleils. Limitations on budget do not permit the kind of detailing which transforms timber, knots and all, into visual delight. Yet, in the hands of skilled designers, Waingels’ volumes and daylighting have been manipulated to create a cheerful educational environment, both indoors and out.