retaining wall issues

[boiker]

we allow retaining walls in the required yards, only because much of the old part of town has built with the roads much lower than the general grade of land. What we generally get is a 2-6 foot steep slope in the front yard of homes to the sidewalk edge at the street level.

we currently, weakly, define a retaining wall can be no higher than 3 feet. If it needs to be higher than 3 feet it should be terraced with level ground, then the wall can go up another 3 feet and so on.

What are other communities regulations on these walls?

We just recently had a case where the homeowner has about a 5 foot drop from his front yard to the sidewalk, his old limestone block retaining wall failed and he was going to replace it with a new concrete wall. We told him three feet, terrace, 2 feet was the limit to what he could do.

 

[Bullwinkle]

We restrict retaining walls within the setback areas to no greater than 18" above "original, natural grade." They can go up 18", stepped back with level ground, up another 18", etc. (As you can imagine, there are a number of creative attempts to interpret "original, natural grade.") Outside the setback areas, there is no limit. My building inspector is pretty tough on them, though, and the cost of engineering and building a safe retaining wall much higher than five or six feet pretty much eliminates taller walls.

In your example, why didn't you consider the existing (but failed) wall as a nonconforming structure and allow him to repair it? I would have under our Code.

 

[boiker]

we would have, except that he completly removed it. the non-conforming structure is gone. Our code says that you can make general repairs and maintenance to non-conforming structure, but once it's gone, it's gone. non-conformity disappears. Now he has to meet code. If someone has a non-conforming garage, you don't let them demolish it and then rebuild on the same spot. It has to now meet the code.

Sounds like your code is more strict than ours. only giving them 18". Do you specify how wide the terrace must be? I don't even think the building department regulates retaining walls here.

 

[ambmason]

Wouldn't the retaining wall qualify as a fence if it extends above grade? We allow retaining walls to be at a height as needed with city engineer approval, but if it extends above grade it would be considered a fence and have additional regulations on height and setback. We have had people try to claim that it isn't a fence, but if it is above grade there won't be any earth to retain.

Becuase retaining walls are found adjacent to streets and city sidewalks most often, they can't extend above grade by our regulations that require fences be setback ten feet from the right-of-way line.

 

[boiker]

fences are only above grade

if i could show you a picture i would. the retaining wall would not be above the grade of the front yard. It would be installed at the grade of the sidewalk. If you faced this guys front yard and stood on the sidewalk and stuck your arm straight out, you would touch the level grade of his yard. The wall would be about shoulder hieght on me, about 5 feet high. This wall would only go to the grade of his lawn. i am just curious how other towns regulate retaining walls.

 

[Bullwinkle]

boiker wrote:
Sounds like your code is more strict than ours. only giving them 18". Do you specify how wide the terrace must be? I don't even think the building department regulates retaining walls here.

We don't specify the width of the terrace.

The quickest way to stop a huge retaining wall, and the visual intrusion that a huge wall often creates, is to ask the contractor for an engineer's stamp on his retaining wall plans. They real quickly figure out that they can more easily have a series of two or three smaller walls with terraced lawns, or sometimes patios, in between.

We are on a lake, with a lot of second homes, so most of our retaining wall issues come up on the lakeside of very high end properties. It is amazing how visible a large retaining wall is from the water. By the way, I'm not talking about sea walls or other water's edge retaining walls. Those are regulated by the State. Almost regulated out of existence, actually.

 

[Zoninguy]

Retaining Walls

With respect to calculating height, if the retaining wall is within the required front yard, it is treated the same as a fence. Generally, 42 inches is the maximum in the front yard. If you construct a 3-foot wall and install a 3-foot railing above for safety, then you have created a 6-foot high structure. In order to exceed 42 inches in height, a variance procedure is required.