Air seal the trim the first step is air sealing the finish trim and enclosure around the attic hatch.
How to seal attic access hatch.
How to seal knee wall doors.
Affix foam insulation to.
Use spray foam to air seal these.
Remove your existing attic hatch and measure its size.
Weatherstrip the attic access hatch or door.
From inside the attic check for any openings holes or fenestrations into the knee wall surrounding area.
Sealing the attic hatch or door finish up by sealing the access hatch with self sticking weather stripping.
Carefully pull down the finish trim.
Apply weather stripping to the door to create a seal.
Pray that the installer used finish nails and not say ring shank nails.
How to insulate and air seal an attic access hatch.
The stops provide a wider surface for attaching the weatherstrip and a space to mount hook and eye fasteners.
The insulation will both slow heat loss and add ballast to the hatch to improve the seal at the weatherstripping.
Seal the attic access.
Apply self adhesive foam weatherstrip tape to the top edge of the stop.
Cut 1 3 boards to fit the perimeter of the opening and nail them on with 6d finish nails.