Summary of Main Issues

IETC Side Event at UNEP Governing Council
6 February, 2001 - Nairobi, Kenya

1. Background

GHG emissions and energy demand are high on the global environmental agenda. With the uncontrollable pace of urbanisation and the consequent rise in energy demand for private and public consumption and for economic activities, there is an urgent need for energy efficient urban planning and construction.

In 1999, construction activities contributed over 35% of total global CO₂ emissions - more than any other industrial activity. Mitigating and reducing the impacts contributed by these activities is a significant challenge for urban planners, designers, architects and the construction industry, especially in the context of population and urban growth, and the associated requirement for houses, offices, shops, factories and roads. It is therefore important to encourage environmentally sound management of urban areas through more energy and resource efficient eco-design, architecture and construction practices, taking into account sustainable development objectives.

2. Sustainable Development and Construction

Sustainable development is defined as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs�E In every country, the construction industry is both a major contributor to socio-economic development and a major user of energy and natural resources; therefore its involvement is essential to achieve sustainable development in our society. For example, the construction industry is the European Union’s largest industrial sector, contributing approximately 11% to GNP, with more than 25 million people directly and indirectly involved. However, buildings account for more than 40% of total energy consumption, and the construction sector as a whole is responsible for approximately 40% of all human-produced wastes. Hence, the provision of adequate housing and infrastructure for transport, communication, water supply and sanitation, energy supply, and commercial and industrial activities poses a major challenge.

What is Sustainable Building?

The concept of sustainability in building and construction has evolved over many years. The initial focus was on how to deal with the issue of limited resources, especially energy, and on how to reduce impacts on the natural environment. Emphasis was placed on technical issues such as materials, building components, construction technologies and energy related design concepts. More recently, an appreciation of the significance of non-technical issues has grown. It is now recognised that economic and social sustainability are important, as are the cultural heritage aspects of the built environment.

Still, sustainable construction adopts different approaches and is accorded different priorities in different countries. It is not surprising that there are widely divergent views and interpretations between countries with developed market economies and those with developing economies. Countries with mature economies are in the position of being able to devote greater attention to creating more sustainable buildings by upgrading the existing building stock through the application of new developments or the invention and use of innovative technologies for energy and material savings, while developing countries are more likely to focus on social equality and economic sustainability.

3. Eco-Design, Urban Form and Function

Sustainable integration of buildings and infrastructure requires a major change in urban form and building design. In some new communities, elements of urban infrastructure systems are moving much closer to and even inside the buildings themselves. Increasingly, there is a blurring of the traditional boundaries that separate buildings from their civil infrastructure. In some communities, large distribution grids and remote treatment and generation facilities are giving way to a network of distributed or "on-site" infrastructure systems, with shared elements integrated into the fabric of the built environment. More diverse land use and building types can complement these on-site infrastructure systems, creating self-reliant, mixed developments of housing, commercial space and industry. In these communities, each new housing development is seen simultaneously as a centre of employment, communications and food production, as well as a facility for power generation, water treatment, stormwater management and waste management.

In existing older communities, this type of sustainable integration is more difficult. The rate of technological change needs to be matched to natural turnover rates for the building stock and infrastructure and functional integration of systems must evolve incrementally. The performance of existing systems must be carefully evaluated and forecast in order to allocate resources between maintenance, refurbishment or replacement.

Designers and engineers are faced with an increasing range of options. The life cycle impacts and energy and material flows need to be assessed for very diverse technologies, and for a greater variety of scales and locations. Decision makers need comprehensive models in order to combine the flows from different stocks (i.e., buildings, roads, pipes, wires, etc.) and allow meaningful comparisons between integrated and less integrated systems.

The presence of nature within the built environment can take many forms, depending upon the history and geography of the site and the density of buildings or infrastructure. The existence of natural features such as rivers, geological contours and land unsuitable for building is another factor that allows nature to persist in the urban setting. In some cities, zoning regulations call for plenty of open space, which is often developed as green space. In other cities, there is an unbroken array of buildings, connecting roads and parking areas, leaving little room for nature.

There are typically two types of green space within the urban environment - natural areas and cultivated areas. Natural areas, where human intervention has been limited, are composed of a high proportion of indigenous species. Cultivated areas, deliberately created by humans to embellish the city, are composed of introduced species or horticultural plantings and usually require human intervention. There is considerable overlap between these two types of green spaces, which is important as urban areas continue to evolve in ways that integrate the natural and built environment.

This type of urban biological diversity also has an important role in sensitising humans to the importance of green spaces and natural systems that balance the “inorganic�Ereality of buildings and urban infrastructure. To enhance and reinforce the benefits of urban biodiversity, co-operation is needed between city managers and scientific institutions. New partnerships must be established to provide cities with the benefits of know-how and advances in the biological sciences, our understanding of natural systems, and the integration of sustainable solutions.

5. Issues and Challenges

5.1 Sustainable Building Design and Construction

Sustainable construction is a way for the building industry to move towards achieving sustainable development, taking into account environmental, socio-economic and cultural issues. Recognising this, in 1995 the Comission Internationale des Bâtiments (CIB), the leading international organisation for research collaboration in building and construction, decided to make sustainable construction the focal point of its multifaceted activities. This involved the establishment of an international agenda on sustainable construction to help guide the implementation of sustainable development principles in the construction sector. This international agenda on sustainable construction is based on Agenda 21 and provides a conceptual framework for linking the global concept of sustainable development and the construction sector with other agendas and activities that are appropriately responsive at the local level. The main issues and challenges for sustainable construction are described below.

Management and design are key aspects of sustainable construction, not only in terms of technical matters, but also in relation to social, legal, economic and political issues. This is a complex and difficult area to address, due to the large number of stakeholders involved in the building and construction sector. Building activities range from development to deconstruction, demolition and disposal, and include the operational aspects of each component of the built environment and each phase of the construction process. Some of the requirements for progress in this area include:

• the development of new architectural, engineering and building concepts
• the development, education and training of human resources
• improvement in the environmental quality of construction,
• improvement in the energy efficiency of construction, and
• further research.

Some of the barriers include:

• the demands and expectations of building owners and clients not always taking into account energy efficient building criteria
• the lack of awareness and knowledge of planners, designers and engineers regarding energy and resource efficient building solutions
• the lack of public awareness and involvement
• the inadequacy of standards, regulations and decision making processes, and
• limitations within the design process itself.

Optimising the performance characteristics of buildings and products is a fundamental requirement for improving sustainability. With respect to product manufacture, it is important to reduce the embodied amount of material and energy of the products, to lower emissions from the use of products, to improve their energy efficiency while in use, and to improve the potential for recycling and reuse. With respect to the buildings themselves, environmental objectives are more likely to be met by applying suitable indicators of building performance. In doing this, it is essential to take into account factors such as climate, culture, building traditions, and stage of industrial capacity. Indoor environmental quality is another important consideration to ensure healthy, productive living conditions inside buildings.

Efforts to conserve ecosystems and to reduce resource consumption require the use of renewable or recycled materials and the selection of materials taking into account life cycle “cradle to grave�Ecosts. Energy saving measures, retrofit programs and transportation issues constitute major challenges for the construction sector. Alternative energy solutions such as district heating systems can lead to significant energy and resource savings. Water efficiency and demand management are also required. Other important considerations are the choice of site, the designation of land use, the longevity of buildings, and the use of land for production of building materials.