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What insulation values do I need for my building?

Posted by: Chris Baker on Tuesday, April 16, 2019

This is one of the most frequently asked questions from our architectural clients. While the question seems straightforward on the surface, the answer depends on a myriad of critical factors. Everything from building materials to climate zone location – including the structure's orientation to the sun – has a dramatic effect on insulation requirements.

However, the most important factor we consider from an engineering perspective is whether the building allows for a prescriptive path or a performance-based calculation method.

Small-scale buildings with individual mechanical, electrical, plumbing, and fire protection systems are more inclined to be designed by a prescriptive approach. This is often more clear-cut, but the prescriptive path requires every component of the building to meet or exceed specific performance standards. For example, the roof may require a minimum R-value of 19.

The performance method is often more complicated and requires advanced calculations because it allows more flexibility and tradeoffs when selecting building materials. Large-scale buildings with numerous systems or diverse purposes present more ways to take advantage of the performance-based compliance method. It works so long as the design of the building as a whole is at least as energy efficient as a comparable baseline or reference building.