The road to energy independence is paved with conservation. In spite of new methods of producing ‘clean’ energy, nothing beats conservation as the most cost-effective solution. This is why recent changes to building codes—such as the new National Energy Code of Canada for Buildings (NECB)—have emphasized the requirements for airtight building envelopes and continuous insulation (ci).
In an effort to build more energy-efficient and sustainable buildings, there has been a shift toward energy-efficient lightweight cladding options for the exterior. One such product is exterior insulation and finish systems (EIFS).
In the early 1990s, there were mixed opinions about what could, and what should not, be done with exterior insulation and finishing systems (EIFS) as an exterior cladding. However, at that time over 20 years ago, the EIFS industry began the conversion from barrier wall assemblies to rainscreens. Concerns about face-sealed claddings, due to incidental moisture intrusion, led to EIFS manufacturers incorporating a drainage plane in their assemblies for incidental moisture.
A study by Pennsylvania Housing Research Center (PHRC) showed significant reductions in centre-of-cavity R-value for steel-framed wall assemblies, reducing it by as much as 56 per cent when a framing factor (i.e. thermal bridging) was taken into account to measure R-value.
Exterior insulation and finish systems (EIFS) can economically provide energy efficiency and reduced carbon dioxide (CO2) emission levels. However, without durability as the cornerstone of sustainable design, most other ‘green’ attributes of products or systems are lost. Fortunately, with proper installation and integration, these cladding assemblies also offer long-term performance and durability.
In both Canada and the United States, there is increasing awareness of the building envelope’s role in conserving energy. New energy codes and standards include prescriptive requirements for continuous insulation to minimize heat loss associated with thermal bridging.