Sustainability as a Driving Force in Contemporary Library Design

The drive for energy efficiency arising from a growing awareness of the dangers of climate change is leading to new approaches to library design. The article explores the interaction between library architecture and sustainability by reviewing the many complex strategies employed for saving or recycling evermore scarce natural resources. Although the focus is upon energy consumption, the article also investigates how concepts of comfort and climate are changing under the impact of environmental sustainability. These topics are discussed mainly in the context of public and university libraries built over the past decade, with some reference to library designs still awaiting construction. The methodology is developed primarily through comparative case studies, exploring the approach to environmental sustainability under a number of headings drawn from widely employed environmental assessment methods such as BREEAM (Building Research Establishment Environmental Assessment Method), commonly employed in the United Kingdom and much of Europe; and LEED (Leadership in Energy and Environmental Design), the assessment tool frequently used to anticipate the environmental credentials of projects still on the drawing board in the United States and Asia. In many ways the architectural approach to the twenty-first century library is returning to the roots of the modernist library found in Scandinavia with its emphasis upon high levels of daylight, natural materials, social harmony, and contact with nature. Concerns over climate change and the consequent drive for energy efficiency is leading to new approaches to the design of libraries and the reshaping of existing ones. Greater attention is being paid not just to fossil 191 sustainability in contemporary design/edwards fuel energy consumption but to a wider range of environmental and ecological issues. In many ways the architectural approach to the twenty-firstcentury library is returning to the roots of the modernist library found in Scandinavia with its emphasis upon high levels of daylight, natural materials, social harmony, and contact with nature. The article explores the interaction between library architecture and sustainability by reviewing the many complex strategies employed for saving or recycling evermore scarce natural resources. Although the focus is upon energy consumption, the article also investigates how concepts of comfort and climate are changing under the impact of environmental sustainability. These topics are discussed mainly in the context of public and university libraries built over the past decade, with some reference to library designs still awaiting construction. The methodology is developed primarily through comparative case studies, exploring the approach to environmental sustainability under a number of headings drawn from widely employed environmental assessment methods such as BREEAM (Building Research Establishment Environmental Assessment Method) and LEED (Leadership in Energy and Environmental Design). BREEAM is commonly employed in the United Kingdom and much of Europe, while LEED is the assessment tool frequently used to anticipate the environmental credentials of projects still on the drawing board in the United States and Asia. Both are beginning to be used to steer evolving designs for libraries toward greater sustainability. A typical example is the new library at Aberdeen University, designed by the Danish architectural practice of Schmidt Hammer Lassen (fig. 1). In achieving a BREEAM excellent rating, this library is generously daylit with solar gain and winter heat loss limited by the use of high performance glazing and an active facade. Added to this, the library roof is used not only to generate electricity (by employing photovoltaic panels) but also to collect rainwater to flush toilets. This library is typical of the increasing impact that environmental accreditation is having upon design. The prerogative of sustainability is altering the design of new libraries and placing existing ones under ever greater environmental scrutiny. Hence the needs of library staff and users, on the one hand, and the storage of books and their integration with digital media, on the other, are having to adjust to the new meta-narratives of carbon accounting and global warming. The physical dimensions and architectural qualities of library space are increasingly dictated by demands to reduce energy flows, with consequent adjustment to embrace new environmental technologies. Just as the approach to the design of offices and schools is being modified to reduce their carbon footprint, so too with libraries. A key argument in this article is that sustainability is altering typological assumptions as well as detailed architectural approaches, leading to libraries that offer greater user satisfaction and hence are better places to read, meet friends, 192 library trends/summer 2011 or study. In this positive view it is posited that environmental sustainability provides the opportunity to revitalize the design of public libraries and to transform them into structures worthy of their place as carriers of environmental messages in text and built form. Concerns over energy efficiency in particular are encouraging architects to rediscover the environmental approach that underpinned early modernist libraries, particularly those in Scandinavia. This, coupled with the ideals of social sustainability, is leading to a new generation of library buildings where public space for gathering and private space for reading is combined within attractive airy structures. Design Quality, Sustainability, and Environmental Conditions in Libraries The value of good environmental design is often overlooked by those who procure library buildings and draw up the brief. Yet high environFigure 1. Design drawing of central atrium at Aberdeen University Library, designed by Schmidt Hammer Lassen. The natural materials and shape evoke the spirit of the Scottish landscape. Photo courtesy of Schmidt Hammer Lassen. 193 sustainability in contemporary design/edwards mental conditions can make a big difference to the perception of the library and, by extension, to the body that commissioned it, whether it be a municipality (public library), a national government (national library), or a university (academic library). Excellence in design is not, however, easy to measure especially in advance of construction. However, it is now widely accepted that the quality of environmental design affects the attitudes and behavior of library staff and users, particularly in areas such as productivity and concentration levels. There are some pointers that could be employed such as making sure that • energy efficiency is a major factor in the overall design and in the interior library spaces; • the building is connected well with public transport and provides good facilities for those who arrive on foot or by bicycle; • the library is well lit and naturally ventilated, and daylight is available in all reading and study areas; • acoustic quality of the different spaces has been addressed, particularly in open plan and atria-based libraries; • potential adverse conditions such as solar glare, overshadowing, and traffic noise have been resolved; • there are views out onto attractive areas, particularly those with greenery; • interior air quality is moderated by incorporation of interior planting; • there are views within the building that promote use legibility and aid navigation through complex library facilities. The quality of design of civic buildings, such as libraries, affects the choices made by people in the facilities they use and more widely in where they choose to live or work (CABE, 2006, pp. 4, 15). These choices are increasingly influenced by the meanings and values being communicated through sustainable architectural design. Since the main source of manmade carbon emissions follows the burning of fossil fuels (for which over 40 percent are consumed within the building sector for heating, lighting, and ventilation), libraries have their role to play in mitigating global warming and, equally importantly, in sending the message of environmental care through good ecological design. Where BREEAM or LEED are employed, the subsequent library is likely to have a smaller environmental footprint than otherwise. Since libraries, like schools, have the ability to change attitudes through architectural design, architects and their clients need to ensure that sustainable design is visible particularly in the main public spaces of library buildings. Increasingly, there is an expectation that daylight, controlled sunlight, and fresh air should be provided in all or most public parts of the library. This may be on the top floor where the café is provided, in a central atrium, or in study rooms around the edge. A number of surveys have 194 library trends/summer 2011 highlighted the importance attached to more natural conditions inside buildings, and there is increasing evidence that daylight in particular affects the ability to concentrate, especially at the interface between paper and digital media (Baker, 2009, p. 51). Hence reading rooms in particular need to be well lit but without the problems associated with solar gain. This results in reading rooms facing north as an ideal orientation, and where otherwise, extensive solar protection is needed. Libraries as Carriers of Environmental Messages Image is important to library design, and few images today carry more public acceptability or authority than an environmental one. Increasingly public libraries and learning resource centers on university campuses are expected to display best practice in the area of sustainable design. This allows the library to carry the green message into neighborhoods and onto academic courses. Hence sustainability is frequently incorporated into the brief for the design of new libraries and where it is not, architects and engineers have a duty to seek to reduce the carbon footprint of their designs. The role of the library here is important as it stands for knowledge dissemination and intellectual discovery—and nowhere is this more pertinent today than in the arena of global warming and sustainability. It is no accident that many recent public libraries, such as at Brighton in the United Kingdom, designed by Bennetts Associates and in Scandinavia by Schmidt Hammer Lassen (fig. 2), have innovated in the area of energy efficiency. Here green technologies have been visibly displayed in order for the building to carry the message of sustainable design into the community and thereby teach through the building rather than just the books. This issue of wider citizenship learning is a key characteristic of library buildings whether in towns or on university campuses. In this the modern sustainable library begins to engage with the Nordic social democratic library tradition with its blending of art and nature, society and technology (Dahlkild, 2009, pp. 72–74). Like all public buildings, libraries have a major impact on the environment. This extends from the energy used for heating, lighting, and ventilation to energy consumed via computers and in transport reaching the building. In addition, a large amount of water is consumed, and libraries have a big impact on biodiversity via the materials used in construction. Energy consumption is not the only issue, but it is often the driver in terms of legislation and public image. The twentieth century saw the demise of natural energy systems in favor of mechanical plant and imported energy. This resulted in deeply planned libraries that were dependent upon airconditioning and artificial lighting. In these libraries the bulk of energy was used keeping the building cool because of the overdependence on artificial lighting. The twenty-first century appears to be revers195 sustainability in contemporary design/edwards ing this trend, and many former library buildings are being sliced open to allow daylight and ventilation to reach into their core. This improves interior conditions psychologically as well as saving considerable sums of imported energy. The subject of sustainable design is a broad one, but in the context of libraries, there are a number of specific issues to consider. Energy Usage and the Library Environment The bulk of energy consumed in library buildings is to heat, light, and ventilate the interior spaces. Libraries also consume significant levels of energy to power computers and other forms of multimedia. So libraries are high-energy users and should seek to generate their own power (through photovoltaic panels or ground-source heating) wherever feasible. To achieve a low carbon footprint, the library architect needs to maximize daylight and opportunities for natural ventilation, to exploit Figure 2. Diagram showing the main environmental design strategies at Oslo Public Library, designed by Schmidt Hammer Lassen. Photo courtesy of Schmidt Hammer Lassen. 196 library trends/summer 2011 solar energy for wintertime heating and summertime stack-effect cooling, to control excessive solar gains and internal glare, and employ construction materials that have low embodied energy and high recycling potential. These are demanding technically, but when combined with modern library functions, the resulting building becomes a place of distinction, physically and socially. Libraries differ from other building types in their energy profile. Typically a modern office building uses about 30 percent of its total energy consumption for electric lighting. However, in a public library the lighting figure can approach 45 percent. If electricity use is high, the heating load is often lower than in comparable buildings. This is because of the accidental heat gains from lighting and other equipment, and from the high level of people occupation in libraries. So a key principle of library design is to maximize interior daylighting levels and to consider carefully the consequent interaction between lighting, comfort, ventilation, and heating. One trend evident in today’s libraries is the use of highly glazed facades, necessary to reduce the use of electric lighting and hence heat buildup. This is evident in the Brandenburg University Library at Cottbus in Germany, designed by Herzog and de Meuron, and the Seattle Public Library by OMA (fig. 3). Both have facades that are extensively glazed but include large atrium spaces for internal ventilation. Where modern libraries are not wrapped in solar-controlled glass, they still remain extensively glazed, with typically the ratio of glass to solid panel approximating 50 percent. One consequent benefit of the open and transparent library is the way it signals that libraries are for people and not just for books. The problems of overheating and poor energy use have been overcome by using double-skin glass facades. This technology provides the best of two worlds—that of maximizing daylight and that of using waste heat for cooling in the winter and for ventilation in the summer. The double façade offers the library the further benefit of acoustic screening of outside noise. Although double facades are technically complex, they offer better control of heat and light than orthodox facades. In large and prestigious libraries, such as the new wing of the Royal Library in Copenhagen, designed by Schmidt hammer Lassen, the cost is justified by the refined conditions achieved. However, as energy costs rise and carbon taxes are implemented, such technologies will become more commonplace. A related trend is the use of exposed concrete in the structure of libraries to stabilize temperatures (using thermal capacity) and provide balance between the fabric of the building, lighting levels, and associated environmental systems. A good example is Alexandria Public Library in Egypt, which achieves a high-quality interior environment without high levels of imported energy by giving attention to lighting, natural ventilation, and thermal capacity (fig. 4). This equation is a major driver in design where heavyweight structure (for books) is combined with lightweight enclosure (for readers) to produce an attractive and dynamic library interior. 197 sustainability in contemporary design/edwards Figure 3. Seattle Public Library, designed by OMA. The highly glazed façade reduces demand for electrical lighting and makes the interior an external spectacle. Photo courtesy of Brian Edwards. Energy conservation can also be achieved by ensuring the building is well insulated, airtight in construction, and uses such things as sensors to prevent artificial lights being employed when there is nobody present. High thermal mass also helps reduce energy consumption, particularly if the effects of transparency sought elsewhere for aesthetic delight can balance the needs of books and readers. Much can be achieved at little or no extra cost. Simply reducing the footprint of the building to the dimensions needed for natural light to penetrate the full depth of the interior can achieve considerable energy savings. Similarly the employment of atria and roofs that incorporate glazing can help with energy efficiency, especially in larger libraries, and these sunlit spaces can provide social and way-finding benefits. Also the reduction of the surface area to internal volume ratio can 198 library trends/summer 2011 deliver further energy savings (and hence carbon emissions). However, the different nature of libraries can limit the opportunity for sustainable design. The book stack area is normally deep in plan and lit by electric lights, and rare book and map collections require specific conditions for their conservation. But within these constraints, efficiencies can be achieved by, for instance, reducing background light levels and employing task lighting at desks (P. Fisher, personal communication, May 17, 2010). It may be possible to zone larger libraries into areas that can be naturally ventilated, those that need to utilize mechanical ventilation and airconditioning, and those areas which could operate on mixed mode cycles. The latter employing nighttime cooling would be suitable in parts of the library where strict air-quality requirements are not needed, such as staff Figure 4. Interior of Alexandria Public Library, designed by the Norwegian practice Snohetta, exploits the benefits of daylight, cross ventilation, and thermal mass to create comfortable conditions in a hot climate. Photo courtesy of Brian Edwards. 199 sustainability in contemporary design/edwards rooms and in the general book stack collections. However, in the IT areas the standards normally prohibit natural light and ventilation. Security of stock and equipment also poses a limit to the degree of permeability of the building’s fabric. However, it is increasingly common to find stack areas that are enclosed to provide the security and ideal environmental conditions mixed with airy reading and study spaces. This dialogue between mass and light mirrors in some ways the patterns implicit in the use of book and digital media. Zoning so that different conditions exist in different parts of the library is a trend encouraged by sustainability. Since daylighting is critical to energy conservation, roof glazing is often employed to allow daylight to enter from above. Deeply planned public and academic libraries are increasingly designed with large roof lights and stepped cross sections. This allows light to enter the large reading spaces, which are often located on the top floor. Often sun tubes and ventilating chimneys are used, resulting in libraries that have much more active roofs than in the past. The architectural animation of library roofs in the interest of energy efficiency mirrors that of the building facades with their solar shading and dynamic climate screens. A good example is Brighton Public Library, designed by Bennetts Associates, in a large coastal town in southern England. The library, which was short-listed for the Stirling Prize in 2005, has large ventilating chimneys over the main reading room, which takes advantage of the coastal breezes (fig. 5). In turn these refer to the shipping tradition in the English Channel, creating a fusion of environmental and cultural sustainability (N. Chambers, personal communication, May 17, 2010). Cross ventilation can rarely keep a large library cool in the summer months. Over a typical year more energy is used in cooling the building than heating it. Hence the emphasis is normally upon achieving good winter conditions without loss of energy through ventilation. Typically a library needs four air changes an hour for healthy conditions, and to achieve this without heat loss, most large libraries use a heat-recovery system of ventilation tied to passive solar heating and high thermal capacity of the fabric (Latham & Swenarton, 2007, p. 98). However, the question of heating is closely tied to that of lighting in terms of the energy balance. Ideally, the library will have high levels of glazing on all facades in order to maximize interior daylight levels (usually a minimum of 60 percent facade glazing). This, however, leads to problems such as downdrafts near windows, solar heat gain, and glare. So one consequence is the dependence upon solar shading, interior blinds, and perimeter heating in order to provide good comfort levels in the reading or study spaces at the library edge. Another is the prioritizing of reading areas on north-facing facades. As a result of these forces, key decisions regarding architectural design are driven by environmental factors (S. Mikkelsen, personal communication, June 8, 2010). There is increasing use of mixed-mode methods 200 library trends/summer 2011 of heating and ventilation whereby natural and mechanical systems are hybridized in order to get the right balance between summer and winter conditions, and between reading rooms and stack areas. This is evident at the Humanities Archive Library at the University of Copenhagen, designed by Dissing and Weitling, the modern offshoot of Arne Jacobsen’s architectural office.