Retaining Wall

Building Permit Requirements

This guideline is intended to provide the homeowner/contractor with the basic information needed to apply for a building permit to construct residential retaining walls.

These requirements apply to most simple retaining wall projects; however, the Plan Reviewer may determine that unusual circum- stance dictates the need for additional information on any particular project.

Phone (314) 822-5823 Building Department 139 S. Kirkwood Rd Fax (314) 822-5898 www.kirkwoodmo.org Kirkwood, MO 63122  Complete cross-sectional drawing of wall Plans for small residential retaining walls A permit is required for any to scale. complying with the design criteria below retaining wall that is more than 2' in may be drawn by the homeowner/ height above the lowest adjacent  Elevation view from the low grade side of contractor: (Note: The walls shall not be grade and for retaining walls of any wall drawn to scale. subject to any surcharge loading from steep height located in a natural water slopes, driveways, swimming pools and course or drainage swale.  Guardrail details if applicable. Retaining other structures, etc.) walls more than 30”measured vertically to the grade below at any point within The proposed retaining wall is located on a 1. Fill out and sign application for a building 36” horizontally to the edge of the open parcel of land containing a one or two permit. side; are required to have a guardrail or family dwelling. other approved protective measure when 2. Submit two (2) separate copies of your site closer than 2’ to a sidewalk, path, Wood retaining walls not exceeding 6' in plan showing existing structures with the new parking area or driveway on the high height for single tier or 4' in height for retaining wall and its perpendicular distances side. [36” in height for residential or 42” double- tiered (8' total height) walls to the lot lines and from other structures on in height for commercial] No openings designed and constructed in accordance the lot, if any. are permitted in the guardrail that will with the attached "Standard Construction Details and Specifications for Residential allow the passage of a 4” sphere.  Site plans must show water run-off (use Wood Retaining Walls." arrows to indicate flow of water). The lo- Modular block walls pre-approved by the cation of the retaining wall cannot ob- Building Department not exceeding 6' in struct any swales or natural water run-off Example site plan below: height of single tier and 4' in height for unless special provisions are made with double-tiered (8' total height) walls the Building Department. designed and constructed in accordance with the manufacturer's approved  Indicate the height of the wall preferably engineered design specification. Many local by furnishing both the top of wall (T.W.) modular block suppliers have had their and bottom of wall (B.W.) elevations at engineered retaining wall designs, plans reasonable intervals along the length of and specifications reviewed and pre- the retaining wall. The bottom of wall ele- approved so that the homeowner/ vation shall be the finished grade level on contractor can easily obtain their permits. the lowest side. Retaining walls of greater heights, having  Indicate which side of the wall is retaining greater surcharge loading and walls of soil. No part of a retaining wall may ex- different materials or designs than those tend across a property line without a rec- specified above must be designed by a orded Construction and Maintenance Missouri Licensed Professional Engineer. Easement. One copy of the structural analysis addressing the wall design, bearing,  Show location of all easements. overturning and sliding must be included with the plan submittal. The cover sheet of  Show the location of the septic tank and each set of the construction plans for the field if applicable. wall and the cover sheet of the structural calculations must have the original seal and 3. Submit two (2) separate complete sets of signature of the professional. The balance detailed retaining wall construction plans of the sheets within the plans may have drawn to scale containing the following: mechanically reproduced professional seals.  Plan view of the wall at a larger scale for serpentine and similar garden type walls.