Description:Exterior alterations to install fence/retaining wall. applicant agrees to limit height of wall at a maximum 4 feet. walls are not permitted to be constructed along public footway with this permit. footings for "dry-stack" type walls to follow manufacturer's instructions. footings for "traditional" type masonry walls to be 8" thick by 18" wide, minimum 30" to bottom. #4 rebar spaced 4' centers for length of wall.