48. What do I need to do to stop the air leaks?

For a thorough and accurate measurement of air leakage in your home, you might want to hire a qualified service technician to conduct an energy assessment. You may already know where some air leakage occurs in your home, such as an under-the-door drafts, around your old windows, on certain walls and ceilings - but you'll need to find the less obvious leaks and gaps to properly air seal your old house.

You might also want to do a blower door test which depressurizes your home and can reveal the location of many air leaks. A complete energy assessment will also help determine areas in your home that need more insulation. Without a blower door test, there are ways to find some air leaks yourself.
Visual Inspections with a thread and a small light feather, on the outside of your house, inspect all areas where two different building materials meet - exterior corners, outdoor water faucets, siding and chimney areas, areas where the foundation and the bottom of exterior brick or siding meet.

Inside your home, inspect around the following areas for any cracks, gaps, cracks in drywall, around electrical outlets, switch plates, door and window frames, trim, electrical and gas service entrances, crawl spaces doors, baseboards, weather stripping around doors, fireplace dampers and chimney caps, attic hatches, wall or window mounted air conditioners, cable TV and phone lines, dryer vents, other venting and fans - all will help to stop the air leaks.