detail wherein like reference numerals indicate like elements there is seen in fig1 and 4 an insulating enclosure designated generally by the reference numeral 10 the enclosure 10 is made up of assemblage of individual modular elements forming in general a peripheral wall 12 and a top 14 the wall 12 and top 14 when operatively disposed as depicted in fig1 and 4 form a continuous 34 cap 34 or enclosure for an opening designated generally by the reference numeral 16 in a horizontal partition ceiling or floor 18 for convenience the horizontal partition 18 is hereafter referred to as a 34 ceiling 34 18 referring to fig1 and 2 the ceiling 18 includes spaced parallel joists 20 and 22 between which cross braces 24 and 26 extend by way of illustration disposed within the space defined by the joists 20 and 22 and the cross braces 24 and 26 and depicted in phantom in fig1 is a conventional folded pull down stair designated generally by the reference numeral 28 the stair 28 it will be seen includes articulated ladder sections 30 32 and 34 hingedly interconnected so as to unfold when desired to provide a stair from the ceiling 18 to a floor not shown below it a panel 36 is affixed to the ladder section 34 of the stair 28 and lies flush with the surface of the ceiling 18 when the stair 28 is retracted.