Moisture is involved in most building envelope performance problems, including mold growth, metal corrosion, and other material degradation. In fact, home repairs due to moisture-related issues cost an estimated $32B annually, according to the Federal Reserve Bank.
To reduce the risk of moisture damage, builders and contractors need a strong foundation in building science. But there are tools they can use to mitigate those risks in new and retrofit construction. The U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL) Building Science Advisor (BSA) tool can help users prevent moisture risks and improve building performance.
What’s the BSA Tool?
The ORNL BSA tool is a free online assessment tool that gives building professionals instant access to the knowledge of the industry’s best researchers and scientists. The web-based interactive tool provides guidance for durable wall systems based on expert consensus, field data, and hygrothermal modeling.
Initially launched in 2019 for new construction, the BSA Tool enables building industry professionals, including architects, builders, and contractors, to assess the thermal efficiency, mold resistance, and moisture durability of different wall assemblies in the various climate zones across the United States. The BSA was updated in 2022 to allow assessment of wall retrofits and to expand the “help” options.
How the BSA Tool Works
The BSA tool accounts for local climate when assessing a building’s vulnerability to moisture. Using user-provided inputs, the BSA tool provides a risk analysis of the potential for building moisture failure by identifying design flaws likely to occur. The tool also provides users with sources of information to consider before building a new home or performing an energy retrofit.
“Anyone with a basic understanding of building science can use the tool,” according to Andre Desjarlais, program manager for the Building Envelope and Materials Research Program at ORNL. “Users can enter the building zip code to determine what climate zone the construction is in, and they are then prompted to complete a series of questions regarding specific details of the wall assembly”.
The BSA uses the 2021 IECC as an energy performance baseline. Based on that code, users can select whether the building is new construction or a retrofit. The user may then give the wall a name and proceed to choose the various material components (including exterior sheathing type and cavity insulation) within the wall system to obtain the analysis. Once all data fields have been selected, the tool then provides an assessment of whether the wall has sufficient drying capacity to perform well in the chosen climate zone.
The learning section of the tool includes detailed sketches of the components of the building envelope, as well as readings on related topics, including the causes and effects of trapped moisture in wall assemblies.
While the BSA does not provide specific project guidance, such as professional advice or project-specific hygrothermal simulation, the assessment tool includes 75,000 to 80,000 simulations. It covers a broad range of wall construction variables and types.
“The BSA will be updated within the next 6 months to leverage machine learning tools that will help bolster analytical capabilities for users,” Desjarlais said. To date, more than 90,000 users have leveraged the tool, but that represents only a fraction of the potential user base. “We’re hoping to spread the news regarding the availability of the tool to help building professionals nationwide.”
Access the BSA here.