Molson Construction is a strong believer in durability-based design. The National Building Codes of Canada addresses durability only at the design and construction phases, but does not address maintenance, repair or other factors that can limit deterioration after hand-over to the Client. Furthermore, the code is limited to addressing deterioration that directly affects the heath and safety of building users.

Durability may be defined as the ability of a building or any of its components to perform required functions in its service environment for its design service life with intended levels of maintenance without unforeseen cost for maintenance or repair. This definition is adapted from CSA S478:19 Durability in Buildings.

Current practice is to design buildings for "Long life", generally requiring a 50 year design service life, but Molson Construction believes that all buildings should be designed to be "Permanent" with a 100 year minimum Design Service Life, without unforeseen cost for maintenance and repair.

Molson Construction defines a "Durable building" as a structure whereby all of its components perform the required functions in its service environment for one century, without unforeseen cost for maintenance or repair. For this, one must provide intelligent design practices, durable materials, dependable construction techniques, and planned maintenance and repair programs. For example, planned replacement of certain components of the building such silicone sealants are performed every 20 years, whereby high performance low slope roofs can be replaced every 25 years.


Of all the issues that must be considered when building a home, durability has perhaps the broadest impact on long-term performance, the most complex set of physical interactions, and the largest potential economic consequence. Fortunately, many of the best practices intended to improve durability require little more than good judgement and a basic knowledge of the factors that affect building durability. 

Durability-limit states are states in which the structure's safety, serviceability and/or other important functionality is compromised through:

  • moisture
  • sunlight (UV)
  • temperature
  • chemicals
  • insects
  • fungi
  • natural hazards
  • wear and tear
By selecting performance standards for the durability of all construction according to the design use and occupancy, we are able to focus our attention on preventing durability-limit states from occurring before the defined / intended service life of the structure expires.