Draft Proposal CA-12 

This concept has been developed by the DOE Building Energy Codes Program (BECP) as a possible code

change proposal to the Commercial provisions of the 2012 International Energy Conservation Code

(IECC).   Interested parties are asked to submit any and all comments on DOE's initial concepts and draft

code change proposals. For instructions on submitting comments, visit:

www.energycodes.gov/development/commercial/codes/iecc/concepts/

Insulate at Time of Re-Roofing (CA-12) 

Objective: Add criteria to ensure adding insulation is required at the time a building is reroofed. 

Suggested Code Change Proposal

Delete Exception 5 to Section C101.4.3 and add a new Section C101.4.3.1 as follows:  

C101.4.3.1 Reroofing. All roof assemblies that are a component of the building thermal envelope of an 

existing building shall be insulated in accordance with Section C402.2.1 when the roof assembly is reroofed.

Reason:  The current code provisions have an exception that allows buildings to be re‐roofed without

having to insulate the roof when the sheathing or existing insulation (assuming there is any) is not

exposed.  Then the current code goes on to indicate when the roof must be insulated under certain re‐

roofing conditions.  The manner in which this provision is structured is causing considerable confusion in

the application and enforcement of the code.  First, the provisions of Section C101.4.3 require this

situation (as a renovation or repair) to meet the code, then the exception at first indicates the situation

that is exempt.  Finally the last sentence of the exception provides an exception to the exception that

results in a situation where instead of being exempt, certain roof situations must be insulated when re‐

roofed.

The proposed code change addresses the intent in a much clearer and deliberate manner.  It eliminates

the confusing exception and the embodied exception to the exception by dealing directly with the re‐

roofing issue.  The logical application of the code is that when in re‐roofing you have the opportunity to

increase the thermal integrity of the roof, you should be required to do so.  The proposed code change

does this and eliminates the confusion surrounding the application and use of the current code

provisions.  

First consider the distinction that the roof must be part of the building thermal envelope.  This means

that the roof assembly has on one side conditioned space and on the other outside air/exterior

conditions.  If that condition is found, then the code change says to insulate the roof assembly according

to the code, no different than the second sentence in the current exception.  Where the roof assembly is
not a part of the building thermal envelope (e.g., a pitched roof over an attic space), then this provision

does not apply.  This is clearly presented in the proposed code change by applying the insulation

provision to re‐roofing of the roof when part of the building thermal envelope.  If not part of the

building thermal envelope, then there is no need for an exemption since the application of the current

code based on the definition of building thermal envelope would not require insulation on such a roof

assembly.

Cost Impact:  There is no cost impact associated with this proposed change because the current code

also requires insulation of the same roof assemblies when they are re‐roofed.  It is just not as clearly

addressed in the current code as it is in the code change proposal.