Iowa Building Energy Codes

Code Level

Commercial Energy Code - 2012 IECC

Iowa State Energy Code (effective 6/1/2014)

Residential Energy Code - 2012 IECC, with amendments

Iowa State Energy Code (effective 6/1/2014)


2012 IECC Model Residential Code vs. Iowa's 2012 IECC Amendments

Requirement 2012 IECC Model Code IA 2012 IECC Amendments

Wood Frame Wall Insulation

R-value: 20 or
13+5 (CZ 5)

20+5 or 13+10 (CZ6)

R-value: 20 or 13+5 (CZ 5/6)

Air Leakage Testing

3 ACH50 or less

4 ACH50 or less

Duct Leakage Testing
(Post Construction)

Total Leakage:
4 cfm/100 sq. ft.

Leakage to outdoors: 4cfm/100 sq. ft.

Total Leakage:
6 cfm/100 sq. ft.

Duct Leakage Testing (Rough-in)

Total Leakage:
4 cfm/100 sq. ft (if air handler is installed)*

Total Leakage:
6 cfm/100 sq. ft. (if air handler is installed)
3 cfm/100 sq. ft. (if air handler is not installed)*

*With exceptions – see the list of detailed code changes



Authorized by – Legislation & Regulation. The state building commissioner is required to include in the building code provisions that incorporate efficiency. Iowa requires the adoption of a code, based on national model energy codes, for single- and two-family residences.

Adoption of the Iowa State Building Code is voluntary for local jurisdictions, but some provisions like energy are applicable statewide. Jurisdictions are allowed to adopt energy codes that are more stringent than the state code.

Oversight – Code oversight is through the Iowa State Fire Marshal Division, Building Code Bureau.

Code change process – Regulatory. The Building Code Commissioner within the Building Code Bureau initiates the process to upgrade the energy code. Those tentative amendments are approved or rejected by the appointed Building Code Advisory Council.

Code change cycle - Every three years, concurrent with updates to the model energy code.


Enforcement - Building energy code enforcement is part of the duties of local code inspectors for the jurisdiction with authority over the building. If a local jurisdiction has not adopted a code, then plan review can be performed by the state commission.

Implementation/Compliance Studies – The Iowa Department of Public Safety State Building Code Bureau conducted a residential building energy code baseline compliance study in 2011. 

Primary Contacts

Iowa State Fire Marshal’s Office, Building Code Bureau

Iowa Economic Development Authority

Energy Division

Iowa Association of Building Officials