This is a 60 year old house, which my daughter bought 6 years ago Don't know what the original exterior was, but now has siding which is several years old. There is an attic. No apparent leaks in the roof. Working sump pump in the crawl space. Replacement windows were installed last year.. Gas heat, AC which she seldom uses because she prefers fresh air and keeps windows open.
No exhaust fans in bathroom or kitchen.
Any ideas as to how to determine the cause of the odor?
TIA

Sue

and if the closet doors are kept closed, you get the combination of damp and stagnant... perfect place for icks to grow.
check the gutters and make sure that they're not doing something evil like draining half the runoff into the eaves and down the exterior wall (very evil, like call the insurance company kind of evil)
if that's not causing the dampness, and
there's no sign of an actual leaking pipe in the wall (actual condensation or staining of the drywall or the ceiling below) then you might just have damp air... slick surfaces like shoes show mildew and mold first, but eventually, it will get into other things, and that's not good.

the simplest answer in a small space is a bucket of 'damp rid'... I actually keep one in my husband's car, since he can literally fog the windows up just sitting there waiting for me to get out of the market!

and making sure that the closet doors get opened on a regular basis.

Sue

Thanks
Sue