Wates Construction has begun work on the £29m Dixons Allerton Academy in Allerton, Bradford, which will cater for 1,886 students and aims to become a highly sustainable part of the local community.
“We’re making use of a lot of sustainable technologies throughout the building,” says Wates Construction managing director in the North and Midlands Phil Harrison.
“It’s just short of 15,000 sq m so it’s a big floor plate and there are going to be close to 1,900 kids there so it’s a big school at the heart of its community.”
Sustainability is a major part of this project for Wates and for Integrated Bradford Local Enterprise Partnership and Bradford Council, and designer BDP Architects.
“The building has been designed very efficiently so we have a lot of thermal mass, a lot of concrete and a lot of structure in the building,” says Mr Harrison.
“This is so the heating and cooling load are much reduced. The heating is designed on a mixed mode; it’s partially natural ventilation and it uses energy recovery ventilation systems, too.”
The new building will also make use of rainwater harvesting, which reduces the discharge into local sewers and gives the school grey water to use to flush toilets and the like.
“It also has photovoltaics, which generate electricity in the play deck area particularly in the primary school, and solar thermal which will heat the domestic hot water system,” says Mr Harrison.
The ground-source heat pump has been designed by Econic, the heat pump arm of renewable company Myriad CEG, and aims to be one of the most innovative systems of its kind in the UK.
“The original strategy was to look at a deep geothermal system,” says Econic managing director Rob Gardener. “The consultant then introduced some cooling requirements into the equation, so we had to look at another method and a new system.”
The system the team came up with is a modulating ground energy collector, which can be used to heat or cool the building as needed using a network of pipes and boreholes that are connected in sub-sections.
“The system monitors flow and temperature around the different sections of the ground collector, and where there is demand for heating or cooling.
“It will assess the temperature of the fluid in the different sections of the ground and direct flow around the sections which have the most suitable temperatures,” explains Mr Gardener.
The innovative aspect, says Mr Gardener, is that each individual section within the main collection of boreholes is operated by its own circulation pump.
“If there is only a partial load required by the building, you don’t need to push the fluid around the entire section so the system directs flow around a smaller section and you don’t use such a large electricity load,” he says.
The project is being carried out on land adjacent to the existing school buildings, which will remain in use during construction, posing some challenges to the team.
“The fact we’re building it within the existing campus makes it quite interesting,” says Mr Harrison.
“We’re on quite a hillside so we’re having to build the building in step layers as it climbs up.
“It’s always a challenge in terms of location, working within the boundaries of the existing school, working with the topography of the existing site and making sure we liaise closely with the school so that they end up with a building they are immensely proud of.”
Once the new building is completed - it is due to be finished in August 2013 - the old buildings will be demolished to make way for sports facilities the whole community will be able to use.
The team has the added challenge of having to relocate some delicate items from old school buildings to the new ones. “They’ve got a listed tiled mural which is inside the old building that we need to take down and replace in the new school,” says Mr Harrison.
As with all education work, deadlines are immovable, so sticking to the build programme is essential. “It can be challenging working within timescales that can’t move,” says Mr Harrison.
“We also need to plan for the soft landings once the school has opened so they are able to fully utilise the school and get the maximum benefit from it from the day they move in.”
Taking a soft landings approach is extremely important in instances such as this where the building’s performance and the occupants’ enjoyment can both be affected by how educated the occupants are about the building.
“There is nothing worse than not knowing how the building works; it won’t be used to its full potential,” explains Mr Harrison.
“So it’s really important we take them through the technical manuals and videos, but we also have people onsite who can show the occupants how specific things work. It’s also about being there during early occupation,” he says.
The building will be monitored using the building management system to assess the success of the sustainable technologies and so the team can make any necessary adjustments.
And although many of the building’s sustainable elements will not be affected by the occupants, ensuring they understand how to use the building will mean it is used to the best of its capabilities.