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

unconditioned area insulation questions

buildzilla | Posted in Energy Efficiency and Durability on
i’m working a plan with three unconditioned areas in cz-6 and am looking for input on how to treat conditioned/unconditioned transition walls from an insulation perspective:
from top -> down
1. a “bonus-room” (over garage)
— i wanted to be able to throw a space heater in here on occasion and have it retain heat, so i was gonna insulate these exterior walls as if it was conditioned space (ie r-30)
— local energy standards specify that floors should be r-30, but i think that is referring to something like a cantilevered floor over the outside, not sure if it applies to a floor over an unconditioned garage?
— so how to treat the transition wall here because the space could be pretty cold when not heated, should i treat as r-30 exterior, or give some consideration to the fact that the unconditioned space has r-30 exterior walls too?
2. an attached garage
— since under bonus-room, thinking to go r-30 on these exterior walls and r-15 under the slab
— same question as above about the transition walls
— these transition walls are subject to fire-code if that matters from an insulation perspective
3. a 500 sf chunk of a partially finished basement
— seems like i don’t need to go full on r-30 on these transition walls as the unconditioned space will be r-20 foundation walls and r-15 under slab, but what would be pragmatic?

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.


Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |