Introduction to Sustainable Design - Simplified Design of Reinforced Concrete Buildings - page 314

Chapter 12
Introduction to Sustainable Design

Sustainable development is thought to have three components: social, economic and environmental.
In the U.S., the Building Code Requirements for Structural Concrete (ACI 318-11, or the Code) addresses
the minimum design and construction requirements necessary to provide for public health and safety.
By protecting the public's welfare, the Code meets the social implications of sustainable development.

Perhaps less obviously, the Code also allows for the environmental and economic components of sustainable
development. It permits use of environmentally responsible materials and provides durability requirements to
enhance lifecycle considerations in sustainable design. It also permits selection of structural systems to meet
the economic component of sustainable development and benefit the overall lifecycle evaluation of the entire
building. The introduction to ACI 318-11 clearly permits the owner or the Licensed Design Professional to
specify requirements higher than the minimums mandated in the Code. Such optional requirements can
include higher strengths, more restrictive deflection limits, and enhanced durability.

Ultimately, designing sustainably requires early interdisciplinary interaction of all stakeholders in the building
design and construction process, including the owner, architect, engineer, contractor, and material supplier.

Today's best construction techniques and most advanced buildings are likely to become tomorrow's standard
techniques and typical buildings. We continue to incorporate technological improvements in construction so
that we build better. We aspire to build the best that we can and hope that this saves money in the long run—
through longer lasting structures and more efficient operations.

Operating buildings requires a lot of energy; in the U.S., commercial and residential structures account for
about 40% of our total energy use, which is about 10% of the world's energy use (Ref.12.1). Not only does the

125

100 Transportation

75

Industrial

50

Commercial

25

Residential

0

2008 2015 2020 2025 2030 2035

Figure 12-1 Primary United States' energy use by end-use sector for 2008-2035, quadrillion
Btu. Commercial and residential buildings account for about 40% of the total energy demand.