The Great Thermal Mass Myth................
The term "thermal mass" comes up time and time again on building related forums and discussions, yet as a parameter it has one notable feature - it does not really exist.
There is no such thing as "thermal mass" and never has been.
Mass is a simple physical property, in simple terms it's approximately how much a given volume of something weighs at the surface of the earth. This, in turn, depends on the density of the material.
For example, here are some densities for some common buildin
With the exception that what they refer to as "thermal mass" is really just another (spurious) name for heat capacity, and has no units of measurement that include a term for mass.
The easy way to distinguish whether a property is real or imaginary is just to ask what the units of measurement are. For example, we can define power in watts, horsepower or probably a few other less commonly used units. Likewise we can define energy in joules, kilowatt hours etc.
The only a