Libraries and light

Architectural design involves making choices and identifying opportunities, and the best buildings are arguably those in which the various roles of architecture – social, environmental, functional, aesthetic – are positively combined and mutually inclusive. Yet current lighting design guidance, with its emphasis on quantitative criteria such as the recommended levels of illumination, generally fails to take this into account.

A three-year study led by Professor Koen Steemers and Mary Ann Steane in the Department of Architecture, and funded by the Arts and Humanities Research Council, aims to redress this balance in a particular type of building – libraries.

Libraries are the subject of much current debate. The UK Government is formulating its vision for the future of public libraries, and a recently completed consultation phase invited comment on the need to reconsider what kinds of places they should be and what kinds of environments they should provide. Issues such as the commissioning, updating, designing and operating of library buildings are likely to come under scrutiny in response to changing expectations. How libraries are lit, both naturally and artificially, is a major consideration when renovating or designing new libraries because it is intrinsically connected to aspects such as user comfort, energy consumption and use of space.

Library visits

The aim of the ‘Designing with light in libraries’ project has been to create new understanding of the factors that influence the opportunities, and the dilemmas, of lighting strategies, and to marry this with an exploration of how users experience the environment around them. In providing an analysis of how day lighting is being successfully integrated (or not) with other design ambitions, the project will be of interest to librarians and architects alike.

Eight recently completed libraries were visited, seven in the UK and one in Ireland, plus one 1960s ‘benchmark’ library building in Finland, whose designer was the celebrated master of day lighting, Alvar Aalto. The eight contemporary libraries represent a range of uses and lighting strategies, and have all won prizes for aspects of their design. User questionnaires were completed at seven of these buildings and, wherever possible, current librarians were probed on operational issues, and the original designers on their ambitions for daylight.

Let there be light

What is ‘good reading light’? The phrase conjures up an image of a reader near a window, book to hand, the page in question turned towards the light. What the image implies is that the relationship of the reader to the light, the book and the room is important – in other words, that good conditions for reading are a matter of spatial geometry as well as sufficient illumination.

The situation of private reading in a public space is not an issue that is particularly well addressed by current lighting guidelines, which focus more on quantitative than qualitative aspects. To gain knowledge in this area, the project examined the role of ‘good reading light’ in libraries, comparing the contemporary libraries with data gathered by PhD student Oriel Prizeman on late 19th- and early 20th-century libraries, built when daylight was the principal source of task light. In these older libraries, the overall lighting arrangements have typically been informed by considerations of spatial geometry; the library designs ensure that readers are located and oriented to make the most of the natural light.

Analysis of the more recent libraries demonstrated just how complex an issue ‘good reading light’ is, and the extent to which it involves a broad appreciation of people’s response to, and interaction with, buildings. With the availability of artificial light, it has become possible to design library buildings that are larger and can be open for longer. The consequence is that intelligent day lighting has frequently been ignored – the very availability of artificial light seems to be prompting its conspicuous consumption. In fact, having all the lights on in a public building like a library has now come to signal ‘openness’ to such a degree that even buildings designed to be predominantly day-lit are being artificially lit throughout the day. The project therefore underlines the need for consideration of lighting designs that make better sense in day lighting terms: in other words, lighting that consumes less energy yet maintains adequate – and stimulating – lighting conditions as day turns to night.

Room with a view

In any project of this type, it’s important to ask the users themselves what their opinion is of the lighting in their library through user questionnaires. In the course of the project, new ways of monitoring and recording lighting of the interior spaces have been developed to examine the ‘lightscape’ and the design principles at play, and to help the team interpret the responses from the user questionnaires.

A range of qualitative aspects of lighting are being considered by team members, such as mood, lightness and access to view. As an example, one finding has been the fact that users now expect to have access to a view from the library. They may not necessarily be clear about whether the light they enjoy is daylight or artificial light, but they seem to appreciate the additional visual interest and feeling of spaciousness that views can induce. Where libraries did not meet this criterion, users were considerably less positive, even if an interior was potentially well day-lit through narrow side windows, or through larger, high-level windows or roof lights. It would seem that users value the visual release from focused studying provided by low-level windows of any orientation. Effectively, libraries, whether public or institutional, are now ideally a room – or perhaps several rooms – with a view.

On this account, the 1960s Finnish benchmark library, which lacks a view, turned out to be less well liked by its users than the more recent buildings. However, another explanation for this lack of enthusiasm might also be the fact that the library has clearly outgrown the space for which it was originally designed. This illustrates an important dilemma for any library designer aiming to make the most of daylight: in the Finnish library, what was once a generous if highly introverted space is now both gloomier and more constricted in terms of space and light in which to browse.

Future change, future lighting

In seeking longevity, should designers give the potential need for flexibility of library spaces a high priority? A future change of use – or change of layout – could undermine lighting strategies adopted in the original design. This is why assessment of the benefits and drawbacks of flexible spatial arrangements, and potential strategies for expansion, deserve close consideration early in the design process. ‘Designing with light in libraries’ aims to act as a catalyst for higher quality design, guiding how design can be reframed to make the most of light.

For more information, please contact the authors Professor Koen Steemers (kas11@cam.ac.uk) and Mary Ann Steane (mas58@cam.ac.uk) at the Department of Architecture.