Government » Community Development Department » Permits » Building Permits » Building and Land Use Regulations

Retaining Walls

Retaining walls require a building permit under any of the following conditions:

  • The retaining wall is over 4 feet in height when measured from the bottom of the footing to the top of the wall.
  • The retaining wall supports a surcharge load.
  • The retaining wall receives loading from a building or structure directly or indirectly (e.g., via passive soil pressures).
  • The retaining wall system imparts loading onto a building or other structure, whether the building or structure is new or existing.
  • The retaining wall supports a substantially solid fence (fence portion more than 3 feet high) that adds wind loading and/or seismic loading onto the retaining wall. Chain link fences without wood slats, for example, would not trigger this condition.

Retaining walls require a site development permit if they are over 4 feet high or if it supports a surcharge load. A surcharge load can include parking areas, sloping ground surface or soil pressures from adjacent retaining walls.

Retaining walls must be designed by one of the following professionals:

  • Licensed architect
  • Registered civil engineer
  • Registered structural engineer

Requirements

Drawings

Building permits for retaining walls need to include the following drawings:

Plot plan / title sheet

  • Identification of the property address and owner of the property
  • Identify parcel number
  • Property lines defining the parcel
  • All recorded or known easements
  • All existing buildings and accessory building footprints
  • Location and routing of the retaining wall dimensioned from the property lines sufficient to establish location of wall by survey
  • All trees and their associated drip lines, including trees from adjacent property which have drip lines onto the subject property
  • Location and layout of any private sewer disposal system, including septic tank and leach field routing
  • Location of any potable water wells
  • All on site utilities
  • Top and bottom elevations of wall at the beginning and end of wall and at any grade change
  • Set backs
  • North arrow and reference north

Grading and draining plan

  • Existing and finish grade contours above and below the wall
  • Site sections showing toes and tops of slopes
  • Location and routing of the retaining wall(s)
  • Drainage system routing, termination details and specifications

Structural plans

  • Elevation profile of the retaining wall, fully dimensioned and stationed from skewed corners, with elevations shown for top of wall, top of footing, and bottom of footing relative to a specified benchmark, and with finished soil grade elevations clearly designated along the uphill and downhill sides
  • Cross sections thru the wall at each different wall and/or footing section, with:
    • Uphill slopes shown to H/3 beyond the top of the slope
    • Downhill slopes shown to H/2 beyond the toe of the slope, where the “toe” and “top of slope” and “H” are defined by Figure 1808.7.1 of the CBC and CBC Section 1808.7
  • Blow-up details of critical areas, such as piers, intersecting elements, and skewed or 90-degree corner conditions
  • Complete material specifications
  • Listing of items requiring special inspection

Special inspections

Some retaining walls may require special inspections. Learn more about the special inspection program.

Foundation and soils report

A foundation and soils report is required if any of the following conditions exist:

  • Where assumed design soil pressures used are less than 75 psf per foot of depth. This minimum pressure requirement was established for a typical restrained or partially restrained wall, assuming clay soil and a fully drained condition. Exception: Retaining walls that meet all of the following conditions: 
  1. Do not support buildings or structures other than a fence,
  2. Do not have intersecting-skewed or right-angle wall intersections, and
  3. Are allowed to rotate to create active pressure conditions. In this instance, the design soil pressures must be at least 30 psf per foot of depth, per CBC Section 1610.1 and Table 1610.1.
  • When tiered retaining walls are used.
  • When undrained soil conditions are proposed.
  • When an alternative setback or clearance, as provided under provisions of CBC 1808.7.5, is being used.
  • The engineer or architect incorporates allowable resistance design values greater than values corresponding to Class of Materials Item 5 of CBC Table 1806.2.
  • The site is located within an Alquist-Priolo Special Studies Zone.
  • The site has a history of soil related problems (e.g., creep, settlement, lateral spreading, etc.).

The soils report must be prepared by a registered civil or geotechnical engineer.

Waste management

A Construction and Demolition Debris Recycling Plan may be required. If it’s required, you will need to get your plan approved before getting your building permit issued. A final report will be required before your permit can be finalized. Learn more about waste management.

Forms and documents

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