Designs That Work House Plans are developed by BSC to be appropriate for residential projects in specific climate zones. They are fully integrated construction drawing sets that include floor plans, framing plans and wall framing elevations, exterior elevations, building and wall sections, and mechanical and electrical plans. Please note that house plans are posted as examples of high performance housing designs and are not to be used for construction. For more information, see the note on the title page of the plans.

Enclosures That Work are Building Profiles and High R-Value Assemblies developed by BSC to be appropriate for residential construction in specific climate zones.

Building Profiles are residential building cross sections that include enclosure and mechanical design recommendations. Most profiles also include field expertise notes, material compatibility analysis, and climate challenges.

High R-Value Assemblies are summaries of the results of BSC's ongoing High R-Value Enclosure research — a study that BSC has undertaken for the US DOE's Building America research program to identify and evaluate residential assemblies that cost-effectively provide 50 percent improvement in thermal resistance.

Guides and Manuals are "how-to" documents, giving advice and instructions on specific building techniques and methods. Some, such as the Review of Residential Ventilation Technologies, cover multiple examples within a general topic area. Others, such as the Guide to Insulating Sheathing, are focused on a particular concept and its applications. Longer guides and manuals include background information to help facilitate a strong understanding of the building science behind the hands-on advice.

In addition to these longer standalone guides, this section also contains two quick, easy-to-read series. The IRC FAQ series answers common questions about the building science approach to specific building tasks (for example, insulating a basement). The READ THIS: Before... series offers guidelines and recommendations for everyday situations such as moving into a new home or deciding to renovate.

Information Sheets are short, descriptive overviews of basic building science topics, from duct sealing to reservoir claddings. Through illustrations, photographs, and straightforward explanations, each Information Sheet covers the essential aspects of a single topic. Common, avoidable mistakes are also examined in the What's Wrong with this Project? and What's Wrong with this Practice? mini-series.
Information Sheets are useful both as an introduction to building science and as a handy reference that can be easily printed for use in the field, in a design meeting, or at the building permit counter.

Published Articles are a selected set of articles written by BSC personnel and published in professional and trade magazines that address building science topics. For example, our work has appeared in Fine Homebuilding, Home Energy, ASHRAE's High Performance Buildings, The Journal of Building Enclosure Design and The Journal of Building Physics. We thank these publications for their gracious permission to republish.

We are passionate about building science and welcome new opportunities to share information. If your publication needs content about energy efficiency, durability, or other aspects of high-performance building, please contact us at

Research Reports are technical reports written for researchers but accessible to design professionals and builders. These reports typically provide an in-depth study of a particular topic or describe the results of a research project. They are often peer reviewed and also provide support for advice given in our Building Science Digests. The most recent documents posted are at the top of the list below.

Conference Papers are peer-reviewed papers published in conference proceedings.

Building America Reports are sponsored by Building America, part of the U.S. Department of Energy.

Joseph Lstiburek

The function of a vapor barrier is to retard the migration of water vapor. Where it is located in an assembly and its permeability is a function of climate, the characteristics of the materials that comprise the assembly and the interior conditions. Vapor barriers are not typically intended to retard the migration of air. That is the function of air barriers.

John Straube

Low-permeance vapor barriers are widely used on the interior of wall and roof systems in large parts of North America. Many codes and standards imply or even state that low-permeance vapor barriers should be used in all cold regions as well as many moderate climate zones.

The influence of vapor barriers on the hygrothermal performance of wall and roof systems is a function of exterior climate, interior climate, solar absorptance, rainwater absorption, and the vapor and thermal resistance of all of the layers in the system. In many practical situations, a low-permeance vapor barrier will not improve hygrothermal performance and may in fact increase the likelihood of damaging condensation or trap moisture in the system.

This paper will examine the role of vapor barriers on hygrothermal performance with the aid of simple and transparent diffusion calculations supported by measurements from full-scale natural exposure monitoring. The phenomenon of summertime condensation, the drying of roofs and walls, and multiple vapor barrier layers will be explored. The importance of properly assessing both the interior and exterior climate will be discussed. Vapor diffusion control strategies will be presented.

The requirements in the code can be used for wood framed structures with temperature and humidity conditions typical of residential occupancy. Three classes of vapor control are defined depending on...
Very ColdColdMixed-HumidHot-HumidHot-Dry/Mixed-DryMarine
As they are typically used in buildings today, vapor barriers are a cold climate artifact that has migrated into other climates more from ignorance than need. However, they often prevent assemblies...
Very ColdColdMixed-HumidHot-HumidHot-Dry/Mixed-DryMarine
Joseph Lstiburek

Most of us are not aware of just how differently these two barriers work in building assemblies. This article makes the differences as clear as the polyethylene film that should (or more likely should NOT) be in your walls.

Joseph Lstiburek

Good design and practice involve controlling the wetting of building assemblies from both the exterior and interior and different climates require different approaches. Ideally, building assemblies would always be built with dry materials under dry conditions, and would never get wet from imperfect design, poor workmanship or occupants. Unfortunately, these conditions do not exist.