Sustainability
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Green, Sustainable Buildings
Making the Case for Green, Sustainable Buildings
Within and even beyond the construction industry, sustainability
and green construction remain hot topics. Because these subjects
are constantly evolving, staying current requires a bit of effort.
But the “movement” is having an important impact, from
improved rental and occupancy rates to better health and attendance
of building occupants.
In March 2008, the Costar Group Inc. (a commercial
real estate information consultant) conducted a survey of property
investors and tenants regarding green buildings. Their findings
indicate Leadership in Energy and Environmental Design (LEED®)
buildings command rent premiums of $11.24 per square foot compared
to their non-LEED peers and have 3.8 percent higher occupancy. Rental
rates in ENERGY STAR buildings represent a $2.38 per square foot
premium over comparable non-ENERGY STAR buildings and have 3.6 percent
higher occupancy.
Masonry has many attributes that make it green and sustainable,
both as a building material and as a system, including durability,
density that provides thermal mass for walls, and widespread availability.
Standards developments in the sustainability arena support the evaluation
and assessment of tangible benefits of building with masonry.
Green or Sustainable?
The green concept focuses on environmental aspects, whereas sustainability
also includes social and economic aspects. Sustainable development
is intended to balance economic development, social development,
and environmental protection. That need was endorsed by the United
Nations 2005 World Summit Outcome Document and is succinctly illustrated
in the figure below. Although balance is important, achieving it
is not easy. A continuing challenge is to establish, review, and
revise sustainable development criteria and the standards that measure
them in that context, recognizing that none of these aspects of
sustainable development are static fields. While (existing) good
design is likely to satisfy many of these criteria, sustainability
raises the bar: it establishes a way to evaluate the choices designers
and owners make in a systematic attempt to ensure the efficient
use of resources. It challenges everyone to think about present
design to minimize the impact on future generations.
Sustainability has invigorated the design and building communities
and fostered innovation. Green building technology has created jobs
and sparked interest in materials, energy, and building systems.
It aims for comfortable, efficient buildings, from office and commercial
spaces to residential properties. Moving from general concepts to
specific implementation criteria is not easy and can be controversial,
but the potential benefits seem to be worth the effort as evidenced
by the Costar Group survey.
The American Society for Testing and Materials (ASTM),
one of the world’s leaders in standards development, is seeing
sustainability find its way into virtually all industries. Specifically,
environmental considerations are already influencing numerous standards
on construction materials and products. Sustainable development
and green building design will continue to impact masonry materials,
design, and construction.
While masonry already provides significant advantages in this arena,
masonry-related industries continue efforts to increase awareness
of the sustainable attributes of masonry and to improve those attributes
with innovative use of masonry materials and technology. The Masonry
Society has formed a Sustainability Committee that is developing
and disseminating information on sustainable masonry design and
construction. The Masonry Society also offers seminars that provide
information on how to gain LEED points using masonry construction.
In addition to design and construction, materials and products
are a key component. PCA continues to work in coordination with
users and specifiers to bring about changes to national consensus
cement standards. Such changes permit cement producers to optimize
manufacturing technology and available natural resources while providing
required performance and environmental benefits. Example results
include recent changes to ASTM C150, which enable the cement industry
to reduce the energy and C02 footprint of portland cement
by permitting the use of up to 5% ground limestone in cement, but
continue to require the same physical and chemical requirements
that have provided product performance assurance to the marketplace
for decades. Cement users and specifiers should also be aware of
the complete family of hydraulic cements that are available for
use in masonry construction. These include portland cement (ASTM
C150), performance specified cement (ASTM C1157), blended cement
(ASTM C595), mortar cements (ASTM C1329), and masonry cements (ASTM
C91). Masonry cement mortars, which often have less embodied energy
than other traditional cementitious materials for mortar and plaster,
are particularly well suited to today’s construction policies
and the increased emphasis on sustainable development. The National
Concrete Masonry Association (NCMA) and Brick Industry Association
(BIA) are also actively working to improve the sustainable development
attributes of their products.
At some point, the discussion on sustainable structures will involve
life cycle inventory, life cycle analysis, and life cycle cost—where
masonry is strong. These topics focus on the accounting of resource
usage and long term performance, particularly energy consumption,
of buildings. Over time, the development of better data will simplify
the ability to rate building systems and masonry construction should
be viewed even more favorably.
For more information about the material discussed in this article,
consider the following:
Enright 2008: Enright, C., “Rating Green Buildings,”
ASTM Standardization News, ASTM
International, Conshohocken, Pennsylvania, September/October
2008, pages 34-37.
Meadows 2007: Meadows, D., “ASTM Standard Breaks Barriers
to Global Sustainable Development,” ASTM Standardization
News, ASTM
International, Conshohocken, Pennsylvania, November 2007, pages
42-51.
Gorman 2008: Gorman, M. “Seeing Green,” ASTM Standardization
News, ASTM
International, Conshohocken, Pennsylvania, November 2008, page
2.
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