Where to Insulate in a Home
For energy efficiency, your home should be properly insulated from the roof down to its foundation. This includes the following areas:

- In unfinished attic spaces, insulate between and over the floor joists to seal off living spaces below
- In unfinished attic rooms with or without dormer, insulate…
- 2A - Between the studs of "knee walls"
- 2B - Between the studs and rafters of exterior walls and roof
- 2C - Ceilings with cold spaces above
- 2D - Extend insulation into joist space to reduce air flows
- All exterior walls, including…
- 3A - Walls between living spaces and unheated garages, shed roofs, or storage areas
- 3B - Foundation walls above ground level
- 3C - Foundation walls in heated basements, full wall either interior or exterior
- Floors above cold spaces, such as vented crawl spaces and unheated garages. Also isulate…
- 4A - Any portion of the floor in a room that is cantilevered beyond the exterior wall below
- 4B - Slab floors built directly on the ground
- 4C - As an alternative to floor insulation, foundation walls of unvented crawl spaces
- 4D - Extend insulation into joist spaces to reduce air flows
- Band Joists
- Replacement or storm windows and caulk and seal around all windows and doors
Source Material: US Dept. of Energy
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