Having a roof over your head is important, but if its insulation isn’t performing, it could be costing you.
For new construction, architects are responsible for specifying a system that is up to code. Existing buildings are subject to a code compliance update if they undergo major renovation, so if you’re taking on a reroofing project, it’s crucial for you to confirm that the new solution is compliant.
To ensure that your stress levels don’t hit the ceiling and your financial situation doesn’t cave in, take the following steps to specify the correct amount of roof insulation.
1) Follow the Code
The International Building Code (IBC) and International Energy Conservation Code (IECC) are the two primary authorities to follow, and they adopt the ASHRAE 90.1 energy standard. Codes were updated last year and are revised every three years.
Although these bodies are responsible for deciding requirements, your local building department is the only one that counts, explains Darrell Smith, civil engineer and building envelope consultant with Brown Engineering Company, a full-service, multidiscipline engineering firm.
“Typically the local code agencies are about one cycle behind on the model building code, so it depends on whether they’ve passed the 2012 update or are still going off of 2009. Then they’ll write some of their own standards that better fit local situations,” Smith says. “The local officials are the real enforcers in your area.”
Recommended R-values for certain U.S. climate zones increased by five last year (see map for details). It’s important that a staff member or hired contractor is knowledgeable about the code situation, advises Ted Michelsen, president of Michelsen Technologies, a full-service roof consulting firm.
“You have to worry about the actual building code and the energy efficiency requirements to do an acceptable job,” Michelsen says. “Any competent roofing contractor should know those, but you should too.”