Adding continuous insulation to a building increases the effective R-value of the building much more than adding a similar amount of non-continuous insulation (such as in stud cavities). This creates results you can feel, and see.

Top Resources:

Learn more about how using foam sheathing can save energy and increase comfort as it Prevents Thermal Bridging.

Tools & Education

Stop Wardrobe Malfunctions: Don't Eat Your Sweater: Continuous Insulation for Code-Compliant & High Performance Walls

Educational presentation covering resources on using continuous insulation for compliance with the building codes and energy codes.

Foam Plastic Insulating Sheathing Products in Type I, II, III or IV Construction

Research report covering the use of foam sheathing when used as exterior wall sheathing or in exterior walls in Type I, II, III, and IV construction as defined by the IBC. Available as a sealed code compliance report. 

Foam Plastic Insulating Sheathing Products in Type V Construction

Research report covering the use of foam sheathing when used as exterior wall sheathing or in exterior walls in Type V construction as defined by the IBC. Available as a sealed code compliance report. 

Construction Details for the Use of Foam Plastic Insulating Sheathing (FPIS) in Light-Frame Construction

Code-compliant details for the use of foam sheathing as thermal insulation in light frame construction. Available as a sealed code compliance report. 

The Energy Code Myths That Haunt Us

This presentation, given by Jay Crandell (ARES Consulting) and Amy Schmidt (Dow Building and Construction) at the 2018 RESNET Building Performance Conference covers topics in energy code compliance, such as calculating the R-value of a hybrid wall and determining air space performance contributions.

Best Practices

Foundation Insulation & Frost Protection

Foam sheathing is a very effective means of insulating the interior or exterior of foundation walls, preventing heat loss and lowering the risk of condensation issues.

Window Installation in Walls with Foam Sheathing

Four typical methods for window framing are covered here. The installation approaches shown all include windows with integral mounting flanges, and all use taped foam sheathing as the water resistive barrier.

Incorporating Thick Layers of Exterior Rigid Insulation on Walls

Guidance for the use of thick foam (>1-1/2") in wood frame buildings 

Musings of an Energy Nerd: How Much Insulation Is Too Much?

This 2017 Fine Homebuilding article considers two questions: At what point are envelope improvements a waste of money? And what metrics should we use to determine when enough insulation is enough?

Building America Top Innovations 2013 Profile: Exterior Rigid Insulation Best Practices

Field studies by Building America’s research teams show the most effective ways to take advantage of the thermal, air, and vapor resistance properties of rigid foam insulation on walls, roofs, and foundations.

Design Challenges of the NIST Net Zero Energy Residential Test Facility

This paper outlines the ten general principles for the design of net-zero energy capable houses and describes specific strategies and details that were used for the design of the Net Zero Energy Residential Test Facility (NZERTF), a National Institute of Standards and Technology (NIST) laboratory in the form of a typical residence for a family of four that was constructed on the NIST campus in Gaithersburg, MD. 

Practical Research

Assessment of Water Vapor Control Methods for Modern Insulated Light-Frame Wall Assemblies Research Report

A comprehensive assessment of the state-of-the-art of water vapor control for modern, code-compliant, light-frame wall assemblies.

Cladding Attachment through FPIS Research Report

Overview of current knowledge supporting the attachment of cladding through foam sheathing used in exterior wall assemblies to comply with the 2015 editions of the International Building Code (IBC) and the International Residential Code (IRC).

Termite Protection Research Report

Evaluates data on termite hazard and inspection effectiveness, as well as the presence of hidden pathways in assemblies with and without exterior insulation. Recommends updates to current building code provisions.

Air Space R-value Research Report

Airspace R-values should not be used to displace insulation materials required for energy code compliance unless the air spaces are properly constructed to have no air leakage, or the R-value is appropriately discounted for air-leakage.

Additional Information

Save Energy with Rigid-Foam Insulation

A growing number of builders are singing the praises of using rigid-foam insulation between the wall sheathing and the exterior siding, creating a continuous insulating layer. 

Building Envelope Thermal Bridging Guide

This guide from BC Hydro focuses on improving the thermal performance of opaque building envelope assemblies and interface details, providing practical information to meet the challenges of reducing energy use in buildings.

NIST Net-Zero Energy Residential Test Facility (NZERTF)

Designed and built to be approximately 60 percent more energy efficient than homes built to meet the 2012 IECC, the NZERTF is a unique laboratory at the National Institute of Standards in Gaithersburg, MD.

Plastics Energy & Greenhouse Gas Savings Using Rigid Foam Sheathing Applied to Exterior Walls

This analysis is a case study that examines energy savings and greenhouse gas (GHG) emission reductions resulting from the addition of rigid plastic foam sheathing to the exterior walls of single family housing in the United States and Canada.