Place and Time - Sustainable Design: The Science of Sustainability and Green Engineering - page 171

Both risk and reliability are probabilities. People living in or near what we
design, at least intuitively, assess the risks, and when presented solutions by tech-
nical experts, make decisions about the reliability of the designs. They, for good
reason, want to be assured that they will be “safe.” But safety is a relative term.
Calling something safe integrates a value judgment that is invariably accompanied
by uncertainties. The safety of a building, product or process can be described in
objective and quantitative terms. Factors of safety are a part of every design.
Success or failure as designers is in large measure determined by what we do
compared to what our profession “expects” us to do. Safety is a fundamental
facet of our duties. Thus, we need a set of criteria that tells us when designs and
projects are sufficiently safe. Four safety criteria are applied to test engineering
safety 17 :
1. The design must comply with applicable laws.
2. The design must adhere to “acceptable engineering practice.”
3. Alternative designs must be sought to see if there are safer practices.
4. Possible misuse of a product or process must be foreseen.
These four provisions are the starting point for sustainable design.
Sustainability
Their recognition of an impending and assured global disaster led the World
Commission on Environment and Development, sponsored by the United Na-
tions, to conduct a study of the world's resources. Also known as the Brundtland
Commission, their 1987 report Our Common Future introduced the term sus-
tainable development and defined it as “development that meets the needs of the
present without compromising the ability of future generations to meet their own
needs.” 18 The United Nations Conference on Environment and Development
(UNCED), that is, the Earth Summit held in Rio de Janeiro in 1992, commu-
nicated the idea that sustainable development is both a scientific concept and a
philosophical ideal. The document, Agenda 21 , was endorsed by 178 govern-
ments (not including the United States) and hailed as a blueprint for sustainable
development. In 2002, the World Summit on Sustainable Development identified
five major areas that are considered essential in moving sustainable development
plans forward.
The underlying purpose of sustainable development is to help developing
nations manage their resources, such as rain forests, without depleting these
resources and making them unusable for future generations. In short, the objective