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 C1338. 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.