With New York City’s 80×50 initiative to reduce greenhouse gas (GHG) emissions 80 percent by 2050, the stakes are high for the city to adopt progressively more stringent energy codes. Similarly, the Sustainable DC Plan professes the lofty goal of making the nation’s capital “the greenest, healthiest, and most livable city in the nation.”
Many designers and specifiers understand controlling air, vapor, and thermal transfer helps mitigate moisture problems within the building envelope. Moisture accumulation is a performance adversary that can lead to structural deterioration, finish damage, organic growth, and reduced building longevity.
A material’s thermal mass denotes its ability to store heat within a cycle of time. K-values, generally calculated on a 24-hour cycle, are important because they give general references to a material’s capabilities for storing heat. All materials may be considered for use in a thermal mass calculation, but steel, aluminum, and other metal claddings tend to cycle too quickly, while wood tends to cycle too slowly to offer desirable design values.
The 2012 International Energy Conservation Code (IECC) will bring tremendous change to the way buildings are designed, constructed, and renovated. For example, the insulation requirements for masonry construction have been written to higher performance levels. The prescriptive energy code for the masonry industry is based primarily on the requirement for continuous insulation (ci) within the wall envelope. This becomes an issue when one looks at the standard concrete masonry unit.
In response to a national interest in and policies for conservation of energy, model energy codes are striving to advance the way we insulate commercial and residential building envelopes. A continuous insulation system is prominently featured as a solution in the most recent model energy codes because it is an effective means of addressing these challenges.