DOWNLOAD Dr. Allison Bailes’s FREE Series Parallel R-Value Calculator

Calculate the average R-value of an assembly

Wouldn’t it be nice if you could push a button and see how much of a hit the R-value of a building assembly takes when you change the amount of exterior insulation, move the studs closer together, or leave an attic hatch uninsulated?

That’s what this Excel spreadsheet does. Incorporating the physics of series and parallel heat flow, it allows you to play around with the parameters in floors, walls, and ceilings to see what happens to the average R-value of the assembly. It’s great for anyone who makes decisions about how much insulation to use, where to put it, or how assemblies are designed and built. Usable for 2×4 and 2×6 walls as well as Ceilings and Framing Factors.

Series Parallel Tool 2


Series Parallel Tool 1

This tool is used in HeatSpring’s Mastering Building Science course.


About Allison A. Bailes III, PhD

Allison A. Bailes III, PhD, is founder and owner of Energy Vanguard in Decatur, Georgia. Like many in the field of building science and green building, he is multi-faceted: His academic credentials in physics (BS, MS, MST, and PhD all in that field) give him a solid foundation in the science that underlies buildings. Having taught physics at the high school and college levels, he’s adept at explaining technical concepts in a way that people new to green building can understand. In addition, he has practical, hands-on experience. He built a high-performance home out of structural insulated panels, doing much of the work himself, and ran a home performance contracting business. Numerous homes in the Atlanta area had their ducts sealed and crawl spaces encapsulated by Dr. Bailes himself. Between his first and second businesses in this field, he gained more green building experience by working as the regional manager for the EarthCraft House program in the Southeast. What Dr. Bailes has become most known for in recent years, though, is writing the Energy Vanguard blog. In it he covers everything from building science fundamentals to HVAC particulars to big-picture topics like energy security and peak oil. The blog has gained a wide readership in a short time and is often cited and linked to from other websites. In fact, it is the Energy Vanguard Blog that garnered Dr. Bailes an invitation to become a Green Building Advisor.

Allison is currently teaching: