GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Optimum insulation depth

DouglasM4430 | Posted in Energy Efficiency and Durability on

I have seen UK documents online describing declining marginal thermal value as insulation depth is increased beyond an optimum. Please explain or suggest North American references.

I am located in Canada near Detroit – I believe climate zone 5.

Also, can you recommend energy analysis software for both new and energy renovations?

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. matthew25 | | #1

    BEopt is an easy to use software that will let you run as many scenarios with differing insulation levels as you would like.

  2. relztes | | #2

    Every time you double the insulation thickness, you cut the heat loss in half. So imagine a house where 1" of insulation would result in $4000 annual energy bills. 2" of insulation cuts energy use to $2000. 4" gives $1000. 8" gives $500. 16" gives $250. Etc.

    For that first step, you save $2000 by adding 1" ($2000/in). For the last step, you save $250 for +8" ($31/in). Each time you double, there's half as much energy left to save and you're using twice as much insulation, so the value is four times lower

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |