31-1. All applications for building permits shall be accompanied by accurate plot plans, submitted in duplicate, drawn to scale, showing the actual shape and dimensions of the lot to be built upon, the exact sizes and locations on the lot of the buildings and accessory buildings then existing and the lines within which the proposed building and structure shall be erected or altered, the existing and intended use of each building or part of building, the number of families or housekeeping units the building is designed to accommodate and such other information with regard to the lot and neighboring lots as may be necessary to determine and provide for the enforcement of this ordinance. A careful record of the original copy of such applications and plats shall be kept in the office of the building official, and the duplicate copy shall be kept at the building at all times during construction.

31-2. All dimensions shown on these plans relating to the location and size of the lot to be built upon shall be based on an actual survey, and the lot shall be staked out on the ground before construction is started.