Another story from my Zero Carbon Luton newsletter, which I invite you to subscribe to if you’re in the region. This time I’m looking at a pioneering local building.
Luton Sixth Form College is the oldest in the country, and with 3,200 students, one of the largest as well. It’s also a remarkable example of innovation in sustainable architecture, and I recently took a tour.
In 2007, the college announced that it would be rebuilt in its entirety. When the new building opened in 2010, it had a host of sustainability features and one particular claim to fame: it was the biggest geothermally heated building in Europe.
Geothermal heating is unusual, and it makes the most of Luton’s specific geography. Beneath the building is a chalk aquifer, with water running downhill deep under the site. Being deep underground, the water here is a consistent 11 degrees C all year round. So the designers of the new building created a heating and cooling solution tailored to this opportunity.
At one end of the site there is a 50 metre deep borehole, which draws up water from the aquifer. It runs through a heat exchanger in the basement, which extracts warmth from the water. Only the heat is used. All the groundwater is returned to the aquifer through a second borehole at the other end of the site. Through a series of heat pumps, the geothermal system provides the building’s heating and the hot water for kitchens and bathrooms. The same system is reversible in order to cool the building in summer.
The basement is also home to the rainwater tank. Rainwater is harvested from the roof and is piped to all the bathrooms in the building to flush the toilets.
The building is also designed to maximise natural light, with teaching spaces radiating out from a central hub. Light wells cut through to bring daylight to the ground floor. A quiet courtyard garden brings external windows to internal offices. Natural ventilation is provided through automated louvres.
Outside, generous bike parking space encourages students and staff to travel sustainably. A bike maintenance station is available, and apparently there’s a dedicated charge point for e-bikes somewhere on site, though I didn’t get to see it. Not something I’ve seen before, but that I expect will become more common.
There’s more to do. As early adopters, the college has found that the heat pumps are less efficient than the ones available now and they will be replaced in time. An all-electric building is also proving less economic as electricity prices rise, and there are plans for extensive solar arrays on the roof to reduce costs. Electric car charging points are on their way, and we saw the electrician at work as the lighting is upgraded to LEDs throughout the site.
All of this didn’t come cheap – this was a £56 million project, delivered by a major architecture firm. (KSS, whose other projects include the basketball arena for the 2012 Olympics, and Liverpool FC’s training centre.) But this is an efficient, low carbon facility built with an eye on the future. It’s the college Luton’s ambitious young people deserve, and a building to be proud of.
The Earthbound Report 