Durable Concrete
Buildings Home >
Sustainable Design > Durable
Concrete Concrete Achieves The First
LEED® Durable Building Credit For A
High-Rise Condo
by Bob Marshall, P. Eng., LEED AP
 |
| This Toronto high-rise earned LEED certification
with the help of concrete in the Durable Building Credit category
from the CaGBC |
A Toronto high-rise condominium has achieved the first Leadership
in Energy and Environmental Design (LEED) Canada durable building
credit. The building was Silver certified in May 2006 by the Canada
Green Building Council (CaGBC). Because of the durable design of
the concrete structure and the concrete products used in the building
envelope, building owners and occupants will have lower operation
costs and a healthier building envelope system.
Although the U.S.’ LEED program administered by the U.S. Green
Building Council (USGBC) does not currently have a durable building
credit, points are available through Innovation Credits. These points
can be applied for if an innovative green design strategy is used
that does not fit into the point structure of the five LEED categories,
or if it goes significantly beyond a credit requirement and demonstrates
exceptional environmental performance.
The achievement of the first Durable Building Credit was important
to CaGBC’s Durable Building Task Force (DBTF), which was formed
in June 2005 to develop sustainable solutions for the LEED Canada
durable building credit MRc8.
Durable building principles and practices are vital if longer design
service lives are to be achieved.
Poured-in-place concrete with a long design service life contributed
to the achievement of the durable building credit in this 33-story
condo. The concrete also contains supplementary cementitous materials
(SCMs). SCMs, such as fly ash in the concrete, help recycle waste
products from coal-fired power plants. The recycled waste contributions
are recognized in another LEED credit.
The mass of concrete contributes to improved energy performance.
In combination with other energy saving measures, residents will
save an estimated $200,000 annually in common-area energy costs.
In addition to the better bottom line from sustainable design, owners
and occupants will have healthier indoor air quality. Problems of
entrapped moisture causing mold growth in exterior walls can be
prevented if durable design principals are applied.
The trouble, in most cases, is that owners didn’t know their
health was in danger, as the mold growth that was occurring inside
the wall and causing poor indoor air quality was hidden.
The concrete and concrete products provide moisture and mold resistance,
which contributes to a durable building envelope. Concrete, concrete
products and masonry have the highest rating of 0 (zero) in mold
resistance according to ASTM C 1338. Durable building also has quicker
paybacks and lower lifecycle costs. Although the cost of concrete
may have a small increase in initial first-time cost, it has about
a one-year payback. As a result, there are substantial accumulating
savings, as less cost has to be taken out of pocket to put in reserve
for replacement of less durable cladding.
Keep in mind that achieving durable building is a continuous improvement
process. After completing the durable building design tables (templates),
other follow-up measures are required, including documentation of
the quality assurance program, identification of failure categories
and completion of a reserve/capital financial plan or study.
LEED certification and achievement of Durable Building (MRc8) in
Canada, or an innovative design credit in the U.S., will provide
the peace of mind that you have better protection against costly
premature failures and better indoor air quality.
Bob Marshall, P. Eng., LEED AP, is chair of CaGBC’s Durable
Building Task Force, a member of CaGBC’s Technical Advisory
Group, and works as a senior consultant and cladding practice director
at Jacques Whitford Ltd. He can be reached at bob.marshall@jacqueswhitford.com.
|  |
|