Library design sees the light

The staff at Coventry talk about their new library with almost parental pride. They have good reason: nearly fifteen years in the planning, the new building is a landmark on the university campus and in architectural history.

The project to build a new library, for the university’s rapidly expanding student population, had a visionary quality from the outset. The architects and building engineers were asked to design the most energy-efficient and practical building of its kind anywhere in the world. To meet this brief, the designers would have both to return to first principles, looking at the basic physics of building shape, heating and lighting, then apply state-of-the-art technology to realise their ideas.

Peter Reeve, of the Environmental Design Partnership (EDP), describes the early days of the project as an attempt to answer the wrong question. Unusually for a project of this kind, building engineers were brought in early, to experiment with complex computer models of fluid dynamics. EDP argued that instead of this theoretical approach they should begin with the shape of the building, and design engineering solutions with this shape in mind.

The most economical shape is a sphere, an impractical shape for a building. Short of that, in terms of energy and material use and practicality, the most efficient form is a cube. EDP and the architects, Alan Short Associates, agreed on a cubic building with a 54 square-metre floor plan. This is a very deep plan, and posed the designers a fundamental problem: deep buildings are notorious for overheating in the centre.

Their solution was to drop a set of shafts, light wells, from roof to ground floor, which would allow air to circulate and introduce natural lighting throughout the building. In the design, air is drawn in at ground level, heated and controlled for carbon dioxide content, then released into the library, rising naturally through convection to the top floor. Airflow is controlled by a series of dampers, movable blades controlled individually by microprocessors, to prevent draughts.

The library faces particular problems of overheating in the summer. To maintain the internal climate, the building is thermally insulated from the outside, with recessed windows shaded from direct sunlight. The brick exterior, which absorbs solar heat like a storage heater, can be cooled at night with air blasted from vents in the walls. Reeve explains that on a typical summer’s day the heating of the top floor of a building can be enough to prevent air circulation. EDP’s models and computer simulations proved this would not happen in the new library.

The planners’ concern for energy efficiency and the comfort of the library’s users is equally evident in lighting design. Bill Woolhead, Coventry University’s estates manager, remembers visiting national libraries in the US and France, where the variable level of lighting created a ‘feeling of unease’. The Coventry team insisted on individual microprocessor controls on every light, able to vary intensity as well as simply switch on and off. Bookshelf lighting is angled diagonally to reach the bottom of the shelves.

Woolhead is very clear on the practical outcome of this detailed, innovative approach to all questions of design. Over forty years, the library is expected to save £6.4 million in its energy bills compared to a traditional air-conditioned building of a similar size. Industry is equally impressed by the result: Coventry University Library has been named both Best Public Building and Best Building of the Year in the prestigious Brick Development Association awards.

The library’s most important accolade is the enthusiasm of both staff and students. Since its opening in autumn 2000, attendance has doubled compared with the old university library. There are already plans for further expansion of IT and other facilities to meet the continued growth in demand for the library’s services. Bill Woolhead expresses a modest satisfaction shared by everyone involved: “the library breaks new ground in all kinds of ways. So far it’s all gone as planned, and as predicted.”