Insulation, Radiant and Vapor Barriers - Insulation ideas extension that extends past basement

I have a almost sixty year old house. About twelve feet of the back part of my house extends about two feet past the basement wall. The two feet has not installation and it get very cold in my kitchen cabinets. Is there a way I can install some form of installation. I looked at form board, but it look like it won't work because the foam board would be on the outside. The area is partial enclosed, but not interior. Can someone give me some advice. Thank you very much.

Hi Doc, overhangs are a big issue as they allow air to enter and thus become very cold and drafty and with cabinets blocking any heat from that area they can go all the way to outside temps. If you can access the area from the basement, you could blow in cellulose insulation. The cellulose, when blow in at a high density will also block air flow. If you can remove the cover below and access it from the outside, then spray in foam or rigid foam cut to fit and foam seal with a few cans of great stuff. If there is any plumbing out there, you will want to make sure it remains on the warm side of the insulation. The least expensive would be to air seal all leaks and fill the cavity wilt fiberglass insulation. But the FG does not block air, so you must be sure it is well sealed from the outside.

Bud