The Evolution of Design Process - Sustainable Design: The Science of Sustainability and Green Engineering - page 10

Optimize rather than maximize (synergies, less reliance on active, mechan-
ical systems).
Create a livable environment (protect sensitive ecosystems, actively restore
damaged habitats, look for pedestrian-friendly and mixed-use design op-
tions; avoid toxic materials).
The difference between the stepwise and transitional models is that the former
is based on monetary costs, scheduling constraints, and quality; whereas the latter
expands to integrate human health, safety, and comfort as well as ecological
considerations. The transitional model still pays close attention to the stepwise
model's three attributes. In fact, the transitional model requires that even more
scrutiny be given to costs, scheduling, and quality, so every step is reviewed in
light of the preceding and subsequent steps. The dynamic nature of the model
means that more variables are introduced with each step.
The LEED Green Building Rating System was conceived and implemented
by the United States Green Building Council (USGBC) to define and measure
the sustainability of “green buildings.” The USGBC, created in 1993, formed a
diverse committee representing expertise in architecture, engineering, real estate,
environment, and law focused on the creation of a benchmark for measuring
building performance. According to the council, “This cross section of people
added a richness and depth to the process and to the ultimate product.” 7 Since the
introduction of version 2.0 in March 2000, the LEED rating system has begun to
transform building design and construction. One of the important by-products of
the introduction of this system framework is the increased collaboration between
design and construction professionals united by common tools, principles, and
the desire to achieve high-performance buildings (see Fig. 1.4). Benefits of the
program now extend well beyond the building community, as both the public
and private sectors recognize the benefits of sustainable design and now in many
cases require the incorporation of these design principles, providing direct and
indirect financial incentives and recognition. Another ancillary benefit of the
rating system is that it has created markets for green materials. For example,
points are given for reusing building materials, such as old ceiling tiles, which
had previously found their way to landfills.
Sidebar: Applying the Synthovation/Regenerative Model: Green Buildings
The U.S. Green Building Council has established the Leadership in Energy and Environmental Design
(LEED) rating system, which distinguishes “green buildings.” The greater the point total, the more
sustainable the project. The rating system encourages design and construction practices that reduce the
negative impact of buildings. Most of the points are gained using existing, proven technologies. Projects