GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter 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

Unfinished Basement Insulation Requirements – IECC 2009

dirtydan123 | Posted in Energy Efficiency and Durability on

Hello All,

I recently just purchased a new home. When I signed the contract, the local residential building code was to use the IECC 2009 requirements. I built in zone 5. 

As far as I can tell, it explicitly says that basement walls should be insulated.

The builder insulated one wall cavity (approximately 12′ x 4′) and thats it. The entire basement has concrete walls.  Additionally, they did not insulate the ceiling, or the walls against the staircase which I think they are required to do if they did not insulate the basement? 

I am using 2x more natural gas then average in my area for a brand new home. Something does not seem right.  I am very obviously a layman so I don’t want to try and fight the builder to do more insulation without some ammo. I would appreciate any advice. Thanks!

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.

Replies

  1. Expert Member
    Armando Cobo | | #1

    2009 IECC Table 402.1.1 Insulation requirements for basement walls in CZ5 are R10 continuous insulation or R13 cavity insulation. I would make sure your sill plate, rim joist and any opening thru the walls are well sealed and insulated as well. Insulating the ceiling will work if there is a door between floors.

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |