Cut a gauge stake two inches longer than the height of doors, plus the thickness of the finish floor, and mark on the studding for the bottom of the top trimmer for door and window openings. For all window openings, measure down from the top header 5" more than the height of sash for the top of the bottom trimmer. The allowance for the head jamb and sill.

All top trimmers should be doubled, the side trimmers for doors, sash and casement windows, add 3 1/2" to the width of the sash or door for side jambs. For a double hung or weight window, add 6" to the width of sash for jambs and pockets. For a mullion (two windows side by side) allow 5 1/2" more for mullion between windows for weight pockets and jambs. For sash or casement, mullions where there are no weights, allow the width you wish for the mullion casing. (Fig. 12.)

In bearing partitions and walls, truss across the openings. All door sash and casements should be doubled on the side, set the full stud on the outside and double under the top header.