In building safety and construction , a smokeproof enclosure is a type of exit stairwell that has been designed to keep out smoke ( and other combustion products ) in the event of a fire .
Building occupants may more safely exit the building .
In building safety and construction , a smokeproof enclosure is a type of exit stairwell that has been designed to keep out smoke ( and other combustion products ) in the event of a fire , so that building occupants may more safely exit the building .