Sustainable Practices in the Built Environment

Craig Langston, Craig Langston

• Publisher: Routledge
• Year: 2008
• ISBN:
  9781136360626
• Edition: 1
• Topic: Architecture
• Subtopic: Architecture General

Sustainability is a key issue and its impact on the construction industry, as one of the major users of the Earth's resources, is starting to take hold. This book deals with sustainability as it affects the construction industry, looking at the techniques and issues which designers, engineers, planners and construction managers will have to deal with in their day-to-day activities. It covers methods of analysis such as environmental impact assessment and cost-benefit analysis as well as topics on design and energy regulation and conservation. The book is an important introduction to the subject for senior undergraduate and postgraduate students. Given the importance and novelty of the subject, professionals in the construction industry will also find the book valuable.

PART 1

Environmental
quality

The environment and the economy can no longer be treated as independent and the subject of separate policy direction. Rather, the environment supports economic growth and rising living standards, providing vital social amenity that itself encourages human productivity and creativity. Economic well-being supports initiatives that can protect, conserve and improve environmental quality, fund research and assist in new discoveries or better understanding of natural phenomena.

This balance between environmental conservation, which aims to protect natural resources, and economic progress, which aims to develop human infrastructure, is what is known as sustainable development. Too much emphasis on the environmental side will limit the ability to deliver improvements in living standards, particularly for the developing world, while too much emphasis on the economic side will lead to depletion of vital natural resources that cannot be readily recreated.

Therefore sustainable development is one of the most important issues facing the quality of human habitation of the planet in the future, and one which must be addressed now if an effective balance is to be struck. It involves proper valuation of environmental goods and services, taking a long-term view of development decisions, and seeking to provide equity both within the current generation (rich versus poor) and across generations (present versus future).

The construction industry is a major player in arriving at an effective balance, as most new projects involve some form of resource consumption and site modification that, as a general rule, diminishes environmental wealth and increases capital wealth. So projects which minimize impact on the environment while still providing necessary economic and social advantage should be favoured. Such an approach must bring together the two sides of the equation during the decision-making process. Techniques are needed to assist in this endeavour so that a concentration on short-term monetary performance does not dominate.

In fact, a preoccupation with monetary evaluation has worked against the implementation of sustainable practices. Environmental impact and financial return have been separately considered, but seldom integrated into a single decision criterion. This has led to a division of subjective and objective performance measures; the former influenced by political interpretations of societal need and the latter influenced by business goals and profit maximization. Not until subjective and objective criteria can be evaluated together will sustainable development goals ever be realistically approached.

But in reality there is probably no such thing as sustainable development, at least for the majority of new projects that are commenced every day. The same can be said for existing infrastructure, which may have had the added disadvantage of poor environmental design in the first place. Sustainable development is not a point we reach but a journey we take. It is therefore an ideal, a set of goals, an objective to be pursued, but seldom realized. Yet that is not to say that the concept is a waste of effort. On the contrary, every step towards it is a positive contribution. While most projects will consume more resources than they create, projects that are closer to sustainable ideals will increasingly deliver benefits to their owners and users and to society as a whole. Therefore if design can encompass assessment and decision-making processes that address sustainability goals, it is likely that over the long term the construction industry will be able to demonstrate a significant contribution to global resource efficiency.

Many of the major environmental issues that society faces, however, are not related to individual projects or decisions, but rather are the result of vast collections of projects or decisions on a global basis. So how can any one project, or any one country, make a difference to environmental quality? The answer is reflected in the current debate over recycling. It is true that no one person can make a difference by recycling waste products from their own activities, but if everyone does it then a significant benefit can be realized. In the same way, if every project meets strict criteria for design, construction and operation then over a period of time problems like greenhouse gas emissions, global warming, pollution and loss of biodiversity can be turned around. These are international problems but can be overcome by local solutions. Everything is a piece of a much bigger puzzle, so a concerted effort across the board is required.

Yet exponential increases in population growth are the most serious long-term threat, with the capacity to adversely influence all other environmental problems by placing stress on natural systems to support and assimilate activity. The construction industry, in providing additional infrastructure for a growing population, will have even further impact on environmental goods and services, and as such makes an even stronger case to search for ways to make development more sustainable.

The chapters in this part deal with the important area of environmental quality. Chapter 1 discusses the crisis that afflicts the environment and shows the connectivity and complexity of key global problems. Chapter 2 explores the concept of sustainable development and its characteristics. Chapter 3 demonstrates that environmental goods and services must be properly valued and incorporated into economic models so that environmental wealth and capital wealth can be assessed collectively.

Environmental quality is both the start and the end of the sustainable development debate. It is both the rationale and the objective; the problem and the solution. Only through an appreciation of the importance of the environment to human prosperity can development be put into its proper perspective.

1

The planet in crisis

Caroline Mackley

1.1 Introduction

It is commonly accepted that the planet faces an environmental crisis precipitated by anthropocentric activity that is resulting in a reduction in the earth's productive capacity from which serious consequential social and environmental effects are starting to flow. The significance of the problem has given rise to global co-operation in the form of a range of major international agreements constructed with the objective of seeking a balance between the opposing yet interdependent forces of society, economy and environment.

Nowhere is the complexity and importance of this relationship more evident than in relation to the built environment. Constructed facilities are humankind's most important economic, social and environmental investment. When viewed in terms of its economic significance (as measured as a proportion of GDP), the direct and indirect capital flows constitute on average about 40% of national GDP (Bon and Pietroforte, 1999; International Building Research Council, 1999). In addition, 50% of the world's primary energy production is consumed by buildings when both direct and indirect flows are considered together (Levine et al., 1995; Russell, 1998).

It has been noted that our current economic activity has the potential to reduce the capacity of the environment to provide useful inputs to, and services for, future economic activity (Dovers, 1994). Human economic activity is the principal cause of the environmental crisis through exploitation and pollution, and yet such activity relies on a healthy environment for its continuance and productivity. There is hence a vital partnership upon which much depends.

Sustainability relates to the carrying capacity of the planet to maintain life in all its forms. It is often referred to as ‘sustainable harvests’, or in other words, the amount that various resources can be harvested at certain rates indefinitely without decreasing environmental quality or necessitating reductions in carrying capacity. At a global level sustainability is a complex issue and is difficult to determine accurately for any resource (Botkin and Keller, 1995).

Environmental quality and sustainability are closely linked. Future reductions in the quality and availability of natural resources upset estimates of carrying capacity and accelerate the likelihood of significant environmental catastrophe.

The environmental crisis concerns a wide range of matters. The major themes into which concerns are categorized are (a) social and economic dimensions, and (b) conservation and management of the natural environment. Social and economic dimensions concern such issues as poverty, consumption patterns, human population and health. Conservation and management issues cover atmospheric protection, land resources, ecosystem protection and waste management, amongst other things. The three main environmental problems currently facing the planet, however, are climate change, loss of biological diversity and population growth. These problems, as will be shown below, are interrelated.

1.2 Climate change

1.2.1 Atmospheric protection

‘Of all the global environmental problems, climate change is the most pervasively threatening to human well-being and in many respects the most intractable’ (Schipper and Meyers, 1994, p. 21).

The imperative to protect the atmosphere rises out of its various properties and the relationship it has with the maintenance and support of the Earth's ecosystems. It is now generally accepted that a link exists between atmospheric degradation and the onset of climate change and climate variability. Major uncertainties in modern scientific understanding of the causes and effects of climate change remain and thus are the focus of international research efforts. Whilst these uncertainties remain, the ability of governments to ratify increasingly demanding control measures is hindered.

Currently, the major concern in relation to climate change is anthropocentric air pollution in the form of carbon dioxide (CO₂), nitrogen oxides (NO_x), sulphur dioxide (SO₂), methyl chloride and chlorine gas (Cl₂) and methane (CH₄), as well as issues relating to ozone layer depletion. It is a major objective of the United Nations Conference for Environment and Development (UNCED) to ‘improve the understanding of processes that influence and are influenced by the Earth's atmosphere on a global, regional and local scale including, inter alia, physical, chemical, geological, biological, oceanic, hydrological, economic and social processes ... to improve understanding of the economic and social consequences of atmospheric changes’ (UNCED, 1996, p. 2).

In terms of quantifying impacts, atmospheric emissions are generally classified by impact categories instead of pure emissions of CO₂, SO₂, NO_x, etc. Each of these emissions may have impacts under several categories. These categories include global warming, depletion of the stratospheric ozone layer, acidification, nutrification, ecological toxicity and human toxicity (Fossdal, 1999).

1.2.2 The greenhouse effect

It is important to distinguish between the natural and enhanced greenhouse effect. Greenhouse gases play a vital role in maintaining a balance on Earth that keeps the temperature and functioning of ecosystems at a level conducive to human, animal and plant life – a delicate interaction that is not evident on any other planet in the solar system. The Earth's natural ability to balance the chemical composition of the atmosphere to maintain life is what is considered to be the natural greenhouse effect. The chemical composition of the atmosphere enables solar radiation to be absorbed at such a rate as to provide suitable temperature ranges and weather. It is estimated that the greenhouse balance, driven predominantly by carbon dioxide and atmospheric water vapour, leads to a mean surface temperature of the Earth of about 10°C above what it would otherwise be (Lovelock, 1979). Natural fluxes in this balance occur and up until the time of the industrial revolution, the Earth managed these without interference.

It is essential to be cognizant of the fact that greenhouse gases occur naturally in the atmosphere. Table 1.1 provides a summary of the composition of the Earth's atmosphere.

Table 1.1 Composition of the Earth's atmosphere

Gas	Proportion of atmosphere (%)	Flux in megatons per annum	Atmospheric function
Nitrogen	79	300	Pressure builder, fire extinguisher, alternative to nitrate in the sea
Oxygen	21	100 000	Energy reference gas
Carbon dioxide	0.03	140 000	Photosynthesis, climate control
Methane	10^-4	1 000	Oxygen regulation and ventilation of the anaerobic zone
Nitrous oxide	10^-5	30	Oxygen and ozone regulation
Ammonia	10^-6	300	PH control and climate control
Sulphur gases	10^-8	100	Transport gases of the sulphur cycle
Methyl chloride	10^-7	10	Ozone regulation

(Adapted from: Lovelock, 1979, p. 68.)

The enhanced greenhouse effect is caused by the build-up of greenhouse gases beyond known maximum natural atmospheric concentrations. This is compounded by the Earth's reduced capacity to absorb these as a result of the destruction of natural sinks.

Sources of greenhouse gas emissions are well known. Progress has been made in the last two decades towards a reduction in their atmospheric concentrations through a series of mitigation policies implemented as a result of major international agreements, but it should be noted that even if all emissions were to stop today, the atmospheric concentration of many of these substances would continue to increase for decades to come.

1.2.3 Global warming

Global warming is caused by the build-up of greenhouse gases like carbon dioxide, water vapour, methane, chlorofluorocarbons (CFCs), nitrous oxide and ozone which trap energy on the Earth's surface. While the presence of greenhouse gases is essential to the survival of all living creatures, increases upset the natural equilibrium. Scientists have measured a significant rise in the levels of heat-absorbing gases in the atmosphere and these increases give rise to global warming which can result in damaging consequences for the planet.

Historical evidence suggests that discernible climate change occurs in connection with a doubling or halving of atmospheric CO₂ concentrations. At present only about 0.03% of our atmosphere is carbon dioxide (see Table 1.1 above), which relates to approximately 6 gigatonnes of carbon dioxide emission per year (IPCC, 1995). During the most recent ice age 150 000 years ago, it has been calculated that the mean surface temperature of Earth was a mere 5°C cooler than today with corresponding CO₂ concentrations of 170 par...

Table of contents

• Cover Page
• Half Title Page
• Title Page
• Copyright Page
• Contents
• List of Contributors
• Foreword to first edition
• Foreword to second edition
• Introduction
• Part 1: Environmental quality
• 1. The planet in crisis
• 2. Sustainable development
• 3. Accounting for the environment
• Part 2: Development controls
• 4. Environmental law
• 5. Environmental impact assessment
• 6. Environmental policies and strategies
• Part 3: Analytical tools
• 7. Environmental economics
• 8. Cost-benefit analysis
• 9. Estimating social costs and benefits
• Part 4: Project feasibility
• 10. Project selection criteria
• 11. Intergenerational equity
• 12. The measurement of sustainability
• Part 5: Design considerations
• 13. Environmental impact of buildings
• 14. Low energy design
• 15. Embodied energy and recycling
• Part 6: Energy conservation
• 16. Energy quality
• 17. Renewable energy
• 18. Energy regulation and policy
• Part 7: Life-cost studies
• 19. Life-cost planning and analysis
• 20. Determination of the discount rate
• 21. Occupancy costs
• Part 8: Asset management
• 22. Post occupancy evaluation
• 23. Environmental auditing
• 24. Facility management
• Index