If you build landscape retaining walls 4’ or higher please be aware that your municipality may now be requiring that you get a Permit prior to beginning your project and/or to submit a plan for the retaining wall with an Engineer’s Stamp and a Soil Test.
We’ve heard from two members from the west side of the State that have encountered this with two different municipalities (the Cities of Portage and Walker). These municipalities are interpreting the section on Retaining Walls from the Michigan Residential Code of 2015 (below) to apply to Landscape Retaining Walls and enforcing the need for a Permit and, in one of the cases, also the need for a plan with an Engineer’s Stamp and a Soil Test. It’s important to note that nothing has changed with Michigan’s Residential Code (the same Code since 2015), only the interpretation of it by these two municipalities. Please let us know if you are experiencing this in the municipalities you are working in by emailing Amy Upton.
Excerpts from Michigan Residential Code 2015:
• R404.4 Retaining walls. Retaining walls that are not laterally supported at the top and that retain in excess of 48 inches (1219 mm) of unbalanced fill, or retaining walls exceeding 24 inches (610 mm) in height that resist lateral loads in addition to soil, shall be designed in accordance with accepted engineering practice to ensure stability against overturning, sliding, excessive foundation pressure and water uplift. Retaining walls shall be designed for a safety factor of 1.5 against lateral sliding and overturning. This section shall not apply to foundation walls supporting buildings.
The Authority:
• R104.1 General. The building official is hereby authorized and directed to enforce the provisions of this code. The building official shall have the authority to render interpretations of this code and to adopt policies and procedures in order to clarify the application of its provisions. Such interpretations, policies and procedures shall be in conformance with the intent and purpose of this code. Such policies and procedures shall not have the effect of waiving requirements specifically provided for in this code.