Building Science Advisor Tool at The International Builders' Show (2025)

A live demonstration of how the tool works to gauge risk of different insulated wall assemblies

This session at the ProTradeCraft Live Training Zone features Michael Lubliner, a senior energy analyst at the Oak Ridge National Lab, who is demonstrating an update to the Building Science Advisor website tool.

The Building Science Advisor tool helps you visually measure the risk using three points of a triangle: 

• Moisture
• Mold
• Energy leakage

A tiny red triangle is bad, and a big green triangle is good, so I guess size matters in this instance.

You can add, subtract, and change layers in a wall assembly to compare performance and risk. It is a very cool tool and fantastic that remodelers and builders don't need to guestimate how much insulation is needed and where.

This tool could be helpful for residing contractors, remodeling contractors, Design-Build, and new construction.

VIDEO TRANSCRIPT:

All right, so now this is the Building Science Advisor tool. The first thing you do is decide from the climate zone map. You plug in your zip code, and it gives you a dropdown where you pick a climate zone. Then, you select an assessment. The Building Science Advisor allows you to choose between new construction or retrofit. If you select retrofit, it asks whether it is a gut rehab, a rehab from the inside, or a rehab from the outside. Based on that selection, it provides suggestions associated with your rehab method.

Selecting cladding and insulation options

The tool first asks, "What’s my cladding?" Then, you will see a dropdown menu. Right now, we have metal siding as an option.

Next, the tool considers airspace. Is there an airspace or a drainage plane? Is there continuous insulation? If so, how thick is it, and what type is it? Additionally, it asks whether there is a water-resistive barrier and exterior sheathing.

Cold climate wall with continuous insulation

Here’s an example I’m going to run. In a cold climate, we will put two inches of insulation into the wall as continuous insulation (CI). You can select the type of CI material. We have also specified a drained, ventilated airspace and a water-resistive barrier (WRB). You can specify the type of water-resistive barrier. Additionally, the drywall has vinyl paint on it.

Now, we run the analysis and see that the triangle keeps us in the green zone. In Montana, there are no moisture problems in the cladding or inside the wall. The thermal assembly is well above the International Energy Conservation Code (IECC) standard, sitting at about R-22. This demonstrates that with two inches of foam in a cold climate, you achieve good moisture and thermal performance. You want to avoid getting into the red zone.

Same wall, but without continuous insulation

Now, let’s run the same scenario without continuous insulation. Notice that when you remove the CI, your moisture risk increases. This increased moisture risk occurs in cold climates when moisture gets into the wall, hits the cladding, and either freezes or condenses. In addition, the thermal performance is significantly lower, as seen in the R-value drop.

Hot, humid climate with continuous insulation

Here’s an example of a hot, humid climate. This is the identical wall but in a different climate zone. We are looking at two scenarios: an existing cavity and a retrofit.

Initially, we had a cavity with no CI and no insulation—just a typical 2x4 wall, like in an older house in Atlanta. Then, we added insulation and an inch of CI. The results show that the original triangle indicates no increased moisture or mold risk, like when the house had no insulation. However, thermal performance has improved significantly, leading to notable energy savings and increased comfort.

Limitations of the Building Science Advisor tool

It is important to point out that this tool does not replace hydrothermal analysis, such as WUFI analysis, which many architects and engineers use. Instead, it helps reduce risk and may allow you to avoid hiring an architect or engineer for $1,000 or more.

That concludes my presentation. Here is the website—please try it out and let us know your feedback on the Building Science Advisor (BSA).

I also want to acknowledge everyone at Oak Ridge who allowed me to present this today. Thank you very much!

Recorded live at the International Builders' Show, February 2025, in the ProTradeCraft Live Construction Training Zone.