When is a retaining wall not longer a retaining wall?

[Codeguy49]

I'm helping a client who recently purchased a home and on an area of the property where there's a slope so they built 6 ft tall concrete walls on three sides and filled the inside to use it as a garden (without context it would look like someone trying to build garage). They received a SWO and asked for my help.

My solution for them is to backfill the exterior of the walls to no less than 4 ft in relation to the interior fill (4 ft of unbalanced fill max), thereby turning these walls into foundation walls instead of retaining walls. Also, they wouldn't really be foundation walls as there will be no load on top of them so, they're really just concrete walls and I question if the IRC even regulates them. So, concerns of imposed gravity and lateral loads are addressed.

The city's concern (valid to look into as this is near the front on a side yard and near the garage) is that someone could park where the garden is planned to go, bringing up concerns about an imposed lateral soil loads. We have made it clear that large boulders will be placed in front of the garden, making it impossible to park there. There is no proof of adequate draining materials where soil has been placed so my client knowns they have to remove the soil that has been placed at the interior to address drainage concerns.

The city insists these are retaining walls but, in my view, they are misrepresenting their own MC (Municipal Code). They indicated:

"a permit is required for any retaining wall over 4 feet in height or one that supports a surcharge (such as a parked car)"

The actual requirement in their MC indicates the following are exempt from permit:

Retaining walls which are not over four feet in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge or impounding Class I, II or III-A liquids." Their MC exempts a permit for retaining walls not over 4 feet but they are holding onto the measurement piece and I feel the intent of that measurement is to determine unbalanced fill height and overall height for design purposes. This is no longer relevant with the amount of backfill planned.

The IRC defines a retaining wall as:

"A wall not laterally supported at the top, that resists lateral soil load and other imposed loads." The soil is flat on the inside and not on a slope so, drainage issues are addressed, which removes any concerns about hydrostatic pressure. Couple this with 4 ft of unbalanced fill or less and it seems to me that this should qualify these walls to be exempt from permit.

What I cannot find is any language that substantiates when a retaining wall is no longer a retaining wall in terms of unbalanced fill.

Any help would be appreciated.

 

[Yankee Chronicler]

When you say "municipal code," are you referring to a zoning ordinance, or to whatever building code is adopted in your municipality?

If it's the building code, according to UpCodes Washington State has one building code, and Seattle has its own building code. Where is this taking place?

 

[Yankee Chronicler]

What I cannot find is any language that substantiates when a retaining wall is no longer a retaining wall in terms of unbalanced fill.

If the grade (ground level) is higher on one side than on the other, it's a retaining wall. It stops being a retaining wall when the ground level is the same on both sides.

 

[TheCommish]

When it is a sloped grade.

 

[Joe.B]

A picture would help.

 

[Codeguy49]

When you say "municipal code," are you referring to a zoning ordinance, or to whatever building code is adopted in your municipality?

If it's the building code, according to UpCodes Washington State has one building code, and Seattle has its own building code. Where is this taking place?

In WA State, the law allows for non-adoption of Chapter 1. Several jurisdictions here use their Municipal Code as their Chapter 1. This is their MC.

Only Seattle has the ability to have their own code. All other jurisdictions within the state have to adopt what the state adopts. This issue is not in Seattle.

 

[Yankee Chronicler]

In WA State, the law allows for non-adoption of Chapter 1. Several jurisdictions here use their Municipal Code as their Chapter 1. This is their MC.

Only Seattle has the ability to have their own code. All other jurisdictions within the state have to adopt what the state adopts. This issue is not in Seattle.

Okay, so you are under the Washington State IRC with a local chapter 1. The provisions regarding work exempt from permit are in chapter 1. What -- exactly -- does your chapter 1 say about retaining walls and permits?

 

[Joe.B]

What about grading? I re-read the OP and it sounds a little bit like grading... Might be fine, unless it's a floodplain, or a sensitive habitat area, or or or. There's always so much to consider. It's been identified as a code enforcement issue by the local AHJ, and there's a reason for that. It could be because a nosey neighbor doesn't like what they did, and/or there could be a real issue.

Since you indicated that you're "helping a client" and you're coming here asking for advice, I hope you're receptive to what I'm about to say. I'm not criticizing you or your client, and I'm not laying down any law or anything. I'm offering you my opinion, take it or leave it.

Assume the worst on everything. Find out everything you can about the property, setbacks, zoning, land use, etc. Do public records requests.

Ask your client how bad they want to keep this unpermitted work. It may take a survey, site plan, engineered construction documents, and a licensed contractor. It could end up costing significantly more than the work did, and could take a long time to resolve.

Are they willing to jump through all of those hoops? Are you getting paid enough to carry them all the way?

Do not waive your opinion around expecting to change people's minds. Your job is to do whatever it takes get the client what they want? You're not going to get that by changing people's minds about interpretations of the rules. You're going to get that by dotting i's, crossing t's, jumping through hoops, and whatever else you want to call it.

 

[Codeguy49]

What about grading? I re-read the OP and it sounds a little bit like grading... Might be fine, unless it's a floodplain, or a sensitive habitat area, or or or. There's always so much to consider. It's been identified as a code enforcement issue by the local AHJ, and there's a reason for that. It could be because a nosey neighbor doesn't like what they did, and/or there could be a real issue.

Since you indicated that you're "helping a client" and you're coming here asking for advice, I hope you're receptive to what I'm about to say. I'm not criticizing you or your client, and I'm not laying down any law or anything. I'm offering you my opinion, take it or leave it.

Assume the worst on everything. Find out everything you can about the property, setbacks, zoning, land use, etc. Do public records requests.

Ask your client how bad they want to keep this unpermitted work. It may take a survey, site plan, engineered construction documents, and a licensed contractor. It could end up costing significantly more than the work did, and could take a long time to resolve.

Are they willing to jump through all of those hoops? Are you getting paid enough to carry them all the way?

Do not waive your opinion around expecting to change people's minds. Your job is to do whatever it takes get the client what they want? You're not going to get that by changing people's minds about interpretations of the rules. You're going to get that by dotting i's, crossing t's, jumping through hoops, and whatever else you want to call it.

I appreciate the input and advice. I have looked at the GIS map and there are no issues pertaining to setbacks, zoning, land use. This home is not in a floodplain. My client is willing to get an engineer, if needed. We meet with the city on Monday and hopefully we can show them code information to support our direction.

 

[Yikes]

Without a soil report, the typical assumption is that a surcharge load goes through the soil and wall at a 45 degree angle. so if you have an 8" thick wall, retaining of surcharged loads starts at 8" of elevation difference.

To be more precise with the thread title, you are not really asking "when is a retaining wall not a retaining wall?"; you are asking "when does a retaining wall NOT require a permit?"
In your case, the answer is: when it doesn't support a surcharge load.
But how do you prove a negative, especially when the surcharge might occur from a mobile source, as in a car that occasionally gets parked there? Some type of permanent bollard or lightweight component, or a boulder spaced 4' away from the wall would help.

IMO your client should get a permit, if not for the wall, then just for some diagram that shows the boulders/bollards and states that no parking or surcharge will occur on the high side. This protects both them and the city at time of resale.
If not a permit, then your client could propose the boulder, then follow-up with a letter and a photo for the city files for that property.