Start with a washcloth and some rubbing alcohol and gently wipe down where the scratches are. Take a cotton swab and go through each scratch with some rubbing alcohol to make sure they are cleaned ou ... read more
Verify that all window and door seals/weatherstriping is in good shape.
Check to be sure doors and windows are caulked properly (no gaps, cracks or missing).
If you have an attic access, treat it like ... read more