Residential Roof Insulation Requirements

Gables to be insulated as exterior walls.

Residential roof insulation requirements.

R values can be higher for foam insulation and other advanced insulation systems. Recommended insulation levels for retrofitting existing wood framed buildings. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures. Alternatively you can search for your zone by county through energy gov s here.

State applicable energy ashrae zone minimum r value state. Cavity fibrous or cellulose insulation can be installed at levels up to r 15 in a 2 inch x 4 inch wall and up to r 21 in a 2 inch x 6 inch wall. Ak alaska 2012 alaska building energy efficiency standard 7 r 35 8 r 35 9 r 40. Mandatory minimum r 22 attic insulation unvented attics must be air sealed at roof deck eaves gables and penetrations.

Add insulation to attic. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. Insulating a roof is perhaps the easiest of all the energy saving home improvements. Refer to the requirements for each building envelope area based on your project s climate zone.

Existing 3 4 inches of insulation. Determine your climate zone. Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value. Insulation climate zone requirements.

See the department of energy s doe ranges for recommended levels of insulation below. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.

Minimum insulation r value requirements by state. Climate zones 1 5 and 8 16 wall assemblies must not exceed a maximum u factor of 0 051 climate zones 6 7 wall assemblies must not exceed a maximum u factor of 0 065. Mineral wool rolls are ubiquitous and cheap meaning a whole roof on a standard home could be insulated to the recommended 270mm with a spend of little more than 200. It s also within the capability of most diyers although not the most pleasant of tasks.