Towards Sustainable Infrastructure Development in Africa
Towards Sustainable Infrastructure Development in Africa:
Design Principles and Strategies for Lifespan-Based Building Performance
1Agyefi-Mensah, S., 2Post, J.M., 3Egmond - de Wilde De Ligny, E.L.C. van, 4Badu, E. 5Masi Mohammadi
Abstract
Societies and economies the world over develop on the wheels of infrastructure. In Africa, it accounts for about one-third to one-half of all public investment (Kessides, 1993). Significant about infrastructure in general, however is the fact that they have very long lives. Consequently, their impact on capital investment, resource utilization, the quality of the environment and overall quality of human life can be very significant. It is important therefore that they meet performance requirements in terms of economic, ecological and social sustainability. By the same token, their long lifespan fraught the design task with enormous amount of uncertainties, compounding the already ill-defined nature of design problems. Given that change is importune, and the fact that it is impracticable to foresee all the changes that will occur over time, a defining characteristic of all infrastructure will be the capacity to respond to change. Focusing on the case of buildings, this paper presents a discussion on some design principles and strategies which assure responsiveness to change and hence sustainable performance. Although the concepts have been advocated for over half a century now, studies show that they still remain marginal to the design profession. To clarify the concepts research questioning and extension of knowledge, this paper seeks to examine their basic tenets with the view to harmonize the core principles and strategies. A literature review method is used with examples from field observations where necessary. The paper first attempts to review and harmonize these principles, and highlights the practical usefulness. It then highlights the implications for research and development as well as technology capacity building for sustainable infrastructure development in Africa.
Keywords: Lifespan, sustainability, performance, change, functional, adaptable, infrastructure
1Stephen Agyefi-Mensah, PhD Candidate, Technical University of Eindhoven, (TU/e), The Netherlands, .
2 Jouke M. Post, Professor of Architecture and Building Technology, Technical University of Eindhoven, (TU/e), The Netherlands, .
3 Emelia L.C. van Egmond-de Wilde de Ligny, Assistant Professor of Innovation, Technology & Knowledge Transfer for Sustainable Construction, Technical University of Eindhoven, (TU/e), The Netherlands, .
4Edward Badu, Associate Professor of Building Technology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana.
5Masi Mohammadi, Lecturer in Building Technology (Domotics) - TU/e (The Netherlands
1. Introduction
Societies and economies the world over develop on the wheels of infrastructure. This is to say that infrastructure makes available the physical structures such as roads, railways, ports and harbours, water supply systems, sewers, electrical grids, telecommunication systems and buildings needed to provide the commodities and services essential to enable, sustain and enhance societal living (Fulmer, 2009). This facilitates production which forms the basis for socio-economic development and improvement in the quality of life.
The multiple forward and backward linkages of infrastructure to other sectors of economic growth makes it even more significant to development in Africa. Capital investments in infrastructure contribute to asset formation, employment generation and as security for credit. For example, the construction of buildings such as houses, factories, hotels and offices do not only create employment but also facilitates the production of other goods and services which form the basis for economic growth and improvement in the quality of life. In all countries, therefore, 50% or more of all new fixed capital formation take the form of infrastructural works, including buildings, roads, airports and harbours, dams and power plants, water and sewerage facilities, land reclamation, irrigation and drainage works (Spence et al., 1992). In Africa, infrastructure accounts for about one-third to one- half of public investment and about three to six percent of Gross Domestic Product in Africa (Kessides, 1993). Thus, infrastructure development induces economic growth while at the same time providing the facilities needed to satisfy consumer demands for education and training, health, leisure and recreation, and family life. Sustainability in infrastructure development can therefore not be overemphasized.
For buildings, sustainability is all the more important because of their rather long lifespan, and the myriad of changes that can occur, both foreseen and unforeseen. This impacts the value of capital investment, the environment and the quality of life of its inhabitants in terms of health, comfort and productivity. For example, over a fifty year life, the changes in a building is found to cost approximately three times more than the original building (Brand, 1994). This results because over this period, the service installations change approximately three times along about ten generations of space plan alterations (Duffy, 1990). Leaman and Bordass (1999), attributes losses or gains of up to 15% of turnover in a typical office organization to the design, management and use of the indoor environment. The impact on the quality of human health, productivity and comfort may be underscored by the fact that an estimated 60-85% of human life is spent in homes with half of this in bedrooms (Hassler, 2009), approximately three-quarters of the entire human life. In relation to this, some studies establish a strong link human health and indoor dwelling conditions such as thermal comfort, lighting, noise, moisture and mould (Bonnefoy et al., 2007; Wong, et al., 2009). Further to these, buildings consume about 40% of the world’s total energy, 25% of wood harvest, and 16% of water consumption (UNEP, 2001).
The foregoing evidence suggests that buildings can have significant impact not only on profit-maximization, but the quality of the planet and the life of the people who inhabit it in both the short and long term. They must therefore be sustainable in performance (ISO 15392, 2008). This means, they meet present needs without compromising the need to respond to future qualitative demands (WCED, 1987). Thus, sustainable infrastructure, will meet demand and requirement for the present and the future simultaneously contributing to resource efficiency, environmental quality and quality of life of people.
The purpose of this paper is to present a discussion on some key design principles and strategies which promise to enhance the functional performance and hence sustainability of buildings through the capacity to respond to change. It begins by defining the problem of functional performance deficits in buildings, how these result and the mechanisms users adopt in response. It then discusses some engineering solutions to the deficit and some of the criticisms leveled against their usefulness. This provides the grounds for a discussion on the design principles and strategies considered useful to enhance lifespan performance of buildings. The paper ends by highlighting some implications for research and development as well as technology capacity building.
2. Functional Performance Deficits in Buildings
Buildings change and so the people who occupy and use them. These two seem inextricably bound together. On one hand, changes in climatic conditions and the natural effects of ageing, coupled with wear and tear, make the materials, component and systems of a building subject to decay and depreciation, which if not attended, results in obsolescence and eventual demolition (Douglas, 2002). Buildings nowadays also involve the use of a large number of different materials with different service lives - the actual period of time during which the building or any of its components performs without unforeseen costs or disruption for maintenance and repair. About 150 different materials, with the lifespan of permanent materials varying between 10 - 100 years is reported (Post and Willem, 2001; Athena, 2006). The differential service lives means different parts of the building change at different times and at different rates. This brings about the need over time to ‘prematurely’ change a building component simply because it is part of a system consisting of components with much longer lifespan. In one sense, the shorter lifespan components dictate lifespan changes, and hence the system lifespan as a whole. Considered from another angle, the longer lifespan components can unduly constrain or control the ability of the shorter lifespan components to change by the way they are configured together to function as a whole. This interdependencies creates a non-going tension between the more permanent and relatively mutable elements of the building throughout the lifespan of the building.
The people who use the building, on the other hand, also change and even more rapidly in their requirements as they traverse the trajectory of life. For example, families grow and shrink, changing in composition and size over time, through the addition or departure of a member. Buildings also outlive their first occupants, and different generations of users come into occupancy during its intended lifespan. Occupancy turnover may thus span user of different characteristics at different times. In addition to this, people become physically challenged in time by reason of illness or accident. These changes together change the requirements of people in terms of the use of the building. An even greater challenge is that they are further heightened by the effects of advances in technology, and its impact on social change and the quality of life people seek. For example, increasingly, more and more people are working at home due to advancements in information technology (Kincaid, 2002). Thus, as people’s needs, expectations and lifestyle changes, it becomes necessary to change the building in some way through upgrading, renewal, reconfiguration, modification or adaptation of some form in order to accommodate these changes.
Yet most buildings are rarely designed to change, being designed to satisfy existing forms of use (Gan and Barlow, 1996; Durmisevic, 2006). They are static in form with configurations which lack the flexibility needed to support future changes (Whitchnuil et al., 1999). Over time, therefore, the mismatch between the less mutable attributes of the building and the changing requirements of users reduce the functionality of the building. This widens the gap between the functional and technical lifespan of the building, such that although the building may be physically fit, it fails to support intended or desired requirements for use. This is loss of functional performance. The effect is that the buildings become obsolete, redundant and in the process may be abandoned or become due for demolition with significant impact on environmental quality.
The observation from this is that as a result over time, most buildings fail to meet the requirements for use in an effective way. This mismatch between the technical capabilities of the building and the functional requirements creates a gap between its designed or technical life and the functional lifespan. The useful life of the building shortens making it redundant, obsolete and the subject of demolition. This is reported to have shortened from a technical (designed) life of about 100 years to a functional (use/economic) life between 20 and 35 years (Duffy, 1990; Kendall and Teicher, 2000; Lichtenberg, 2006) (Fig. 2). The impact on the environment, invested capital and the quality of human life cannot be overemphasized. The critical question then is how to design buildings such that they meet requirements in the present and the future, and hence buildings with functional lifespan which approximates as closely to the design life as possible if not equal?
Fig. 1: Performance Deficit in the Life of a Building
Fig. 2: Functional Lifespan Deficit in Buildings (∆FL)
3. Building Change and User Response to Building Performance Deficits
The changes that occur in the life of a building can be many and diverse in character. Broadly however, these may be classified as change in function, change in capacity and/or change in flow (Slaughter, 2001). Changes in function occur in response to higher or new facility performance objectives such as the conversion of a warehouse into an office space or abandoned churches into multi-family residential facilities. Change may also occur in order to meet the need for higher load conditions, for increased operational space (volume) or in response to improved internal or surrounding environmental conditions. For example, the need to add an additional floor to a house or an office building. In yet other cases, change becomes necessary in response to different performance requirements for passage, movement or organization of people and the distribution of goods within or into a facility. Together, these bring about the need to upgrade, renew, modify or adapt the building in some form.
On the part of users, research shows that when an environment fails to meet requirements, users respond by making various forms of changes and adaptations (Bell, Fischer, Baum & Greene, 1996). While some are immediate upon occupancy, others are incremental taking forms such as ‘knocking off’ existing walls, building new walls including illegal expansion of in the case of flats (Brown and Steadman, 1991; Sullivan and Chen, 1997; Wong, 2010). This is so even in public apartments where users do not usually have the freedom to physically alter the building.
Fig. 3: Different forms of adaptations users make in order to meet their requirements for space
Figure 3 above shows different forms of physical alterations users of some public apartments in Cape Coast (Black Star Nurses Flat) and Tema (Kaiser Flats) are forced to make in order to meet their requirements for use. Research in the Netherlands has revealed that in some cases, residents want to move out in search of better accommodation (Durmisevic, 2002). Besides user dissatisfaction, the loss of functionality also creates artificial shortage and compounds the demand problem.
4. Engineering Responses to the Lifespan Performance Problems
The traditional response to building change and the problem of performance deficits has been largely through maintenance and retrofitting on different scales. In arguing for adaptability, Douglas (2002), observes that though useful, this is marginal in effect when balanced against technical difficulties associated, the effect on the building fabric as well as the implications for life cycle costs and waste generation. They are unable to bring the building to the desired level of quality (fig. 4).
