Mechanical insulation keeps Canadians warm in the winter, cool in the summer, and ensures that our energy consumption is under control. Because of this, Canada’s National Energy Code for Buildings, also known as NECB, outlines specific insulation requirements in new and existing buildings. In addition to this, each province and territory can customize their own codes, resulting in a great deal of variation in thermal resistance requirements across the country. In Alberta, the National Building Code – 2019 Alberta Edition is currently in force as well as the NECB.
R-Value: Nominal vs. Effective
Some jurisdictions use nominal values when referring to minimum thermal resistance, whereas others use effective values. Nominal values are the values assigned to the insulation alone. This is easy to determine because the product packaging will already have this number on it. Effective values represent the total thermal resistance of the whole assembly. Depending on the setup, this can result in varying numbers. An insulation professional will need to determine these values accurately to ensure that they meet the code upon being installed.
Insulation Continuity
Another consideration that must be designed into the building is the continuity of insulation. Inappropriately placed gaps and breaks can render the entire insulation system ineffective. This is due to an effect called thermal bridging. The heat will escape through the path of least resistance, so it will seek out any surrounding areas that are thermally conductive and travel through even if there is insulation. To combat this, the NECB requires that insulation be continuous throughout the building envelope and into the inside components. Electrical panels, headers and rim joists, and wall to window interfaces are all areas where thermal bridging must be addressed.
Compliance Paths
Obtaining a building permit requires providing evidence that the design of the building is code compliant. Compliancy can take three different forms:
- Prescriptive. Taking this path is the most straightforward, simply follow all the minimum requirements as outlined in the Code.
- Trade-Off. This path is used when not all minimum requirements can be met, so more must be done in other areas to make up for it. For example, if you need a larger window area than allowed in the code, you may be able to increase wall insulation to compensate.
- Performance. Offering the most flexibility, the performance path requires the services of a design professional. The design can be completely different from the prescriptive requirements with the caveat that it will not consume more energy than a building that meets all the rules in the Code.
Insulation design is an important component of the National Energy Code for Buildings. Compliance will “help save on energy bills, reduce peak energy demand, and improve the quality and comfort of the building’s indoor environment” according to the Government of Canada. If you’re in the Calgary area and looking for an insulation contractor for your new build, contact the experts at Westcal Insulation today!
