San Diego Housing Bubble News and Analysis

You will need a civil engineer to design the retaining wall. City requires it but it is for your own peace of mind as well.

Depending on the size of the cut and the height of the hill these 'little' retaining walls can run into mid 5 figures and easily higher for a big project.

Your kids will be thrilled to see all the heavy equipment and cement trucks rolling up close!

We had a sloped backyard in the house we owned and I figured it would be profitable to put a retaining wall and fill during the bubble years. The same project, though, may not make sense in the current market. Besides, we had to contend with a (possibly uncooperative) HOA.

I think you should start by asking what will you do with a flat backyard. If you are adding a room etc., it may be worthwhile. A garden may not pencil out. If you are planning construction, a good architect may design a structure that hugs the slope nicely and avoids the need to fill.

My house is a raised with a subloor and I built it near a slope and took a deck from the sliding glass door of the great room to the first level of the terrace. This deck is 16 feet wide. I kept within non-engineered required cut and used a stacking retaining wall system. The terrace/patio is about 12 feet wide on average with slate tile and pigmented concrete finishes. Then I put another short wall with no engineering required on the other side of this terrace/patio. I went up from grade about 6 feet total in two steps.The way the contours of my lot work I was able to grade the terrace around the house on both sides and access it from grade without any steps.

I am thinking about cutting further into the hill and building a poured in place concrete walled cabana. This will require engineering. Alternately, cutting a lap pool into the hill, with a bench for the patio or yard, would be cool.

Some friends of mine are going to cut into the slope at their house just far enough to avoid engineering requirements and do some type of masonry hardscape benches with a concrete slab or flag stone patio that you step up to, with a fire pit in the center.

As has been mentioned, by Russell and others, there are two ways to approach it - with the stacked walls (keystone type) and with engineered walls.

We have a lot that slopes down from our house - and built a companion unit and a switchbacked handicap ramp down to it. We have both engineered walls and fill, as well as the stacked walls (on the ramps.

The cost of bringing in fill, or removing fill can vary widely... But it can get expensive depending on how many yards. There is an entire sub-industry of moving dirt in San Diego county.

Thanks for all the input. My idea is extend the flat space of a yard with a slope possibly by 5-10 feet into the slope and build a retaining wall with Concrete blocks, rebar and concrete fill to support the slope.

Something like this

http://www.wayraycontracting.com/images/...

I would like to have two terraces with stairs on one side, not the middle and use the two terraces as flower or garden beds. Sounds simple but im sure its a ton of work.

That looks really nice. The foundations need to be very deep and wide because of the short terrace between combined with the steepness. Sorry, don't
know how much it would cost. The only engineered retaining wall I ever had my hands on was approved by the time I got involved and I only did the foundation. The owner then hired a mason and his helper for $5OO a day(probably $400 now) and did the water proofing drainage and backfill himself with the help of a bobcat opperator who he paid by the hour. He saved a ton of money vs hiring a top notch hardscape guy and got great results.

You do NOT need a civil engineer in San Diego City or County if the retaining wall is under 7 feet. See link here http://www.sandiego.gov/development-serv... (links seems to indicate 6feet but the plans in the permit office have specs to 7ft) If you go to the office for a permit (you need one to build retaining wall more than 3 feet) they have detailed specs on walls up to 7 feet. They are pre-approved engineering plans for retaining walls provided they are 7 feet or less. You can construct a retaining wall over 7 feet but if you do then you have to have your own custom engineering performed. Having the pre-approved plans saves a lot. Make sure the mason/builder follows the plans exactly. The inspecters are sticklers on retaining walls. I have 3ft wall (with fill at base of hill) and then a 7ft wall which cuts into the slope.

At a 2 to 1 slope this provides an extra 20feet of depth to the yard. FYI it took 20 cubic yards of concrete (that is 2 full trucks) just to pour the footings of the concrete wall. The specs they provide seem overkill but I don't worry about the wall as a result.

I'd still engage a civil engineer ... there are a lot of considerations like drainage, surcharge (e.g. if your uphill neighbor has a pool, or a driveway right on the property line) ... and you'll have his/her E&O insurance to supplement your own homeowners insurance if anything goes badly wrong.

4s - thanks for the link. That lays out exactly how I was going to build the wall. My father-in-law is a foreman for construction/ concrete work. The wall would be concrete block with rebar with stone facing and top cap.

I dont own yet but since some of the properties we are looking at have this type of yard, I want to ensure that I can maximize the space. Again thanks for all the input.

First I just have to laugh because my husband and I were just having this conversation yesterday. If I remember right you are looking to buy in SEH as well. I am right with you on gaining some of that slope space.
My brother in Virginia is doing this project as we speak. Russell is right on. My brother rented the bobcat for one day...I can't remember how much. Then paid a driver to clear for $15.00 an hour. It ended up costing him $140 for the driver. He is doing the rest by himself. He was quoted $30,000 for the entire yard, sod, patio, retaining wall, clearing dirt.
He will end up doing it for about $3,000 including a slate patio. The bobcat driver saved his sod and had him go over the patio area several times to compact the dirt which will streamline the patio installation.

If the wall is under a certain height- I believe either 30 or 36 inches no permits are needed either. Depending upon how steep your slope is you can pick up alot of space fairly inexpensively. My backyard is about 100 ft wide and my slope is average steepness. We built a 30" sitting wall (no permits were needed and were able to push back about 10 ft into the slope adding approx 1000 sq ft of flat, usuable yard space. It made a big difference for a few thousand dollars.

A project like The picture you linked could very well require engineering. Not going to argue firmly that it does, I always go to the source of the ultimate decision and don't assume anything, or let people who are making money off the deal have the final word without verifying.

In this case, for example,the house being on top of the project and the steepness put surcharges on the wall that might prohibit the building jurisdiction from allowing prescriptive building.The close proximity of each level's wall combined with the steepness is possibly creating additional requirements beyond the building jurisdiction basic plan. It is always safer to ask.

Also, if there is a home below your home, and you plan on putting in an impervious surface (poured concrete patio for example), that will trigger a requirement for civil - just to show that drainage and grading don't impact the home below you.

The links provided are "engineered plans" prepared by engineers.

One more note. If it is new construction MAKE SURE YOU ASK FOR A SOIL ANALYSIS REPORT! All new construction is required to conduct a fairly expensive soils analysis. I simply asked the builder for a copy of the report that reflected the soil for my lot and he allowed me to photocopy it no problem. It turns out that the nature of my soil was only about 30 to 35% as likely to slide/move (soil viscosity) as the default assumptions used to make the generic standard plans put out by San Diego City/County. In short, my wall is overbuilt/engineered which is no problem with me. Gives extra peace of mind. Don't listen to those that want you to get engineering for anything under 7ft. Just use the standard plans (WHICH WERE DRAFTED BY ENGINEERS). They make very conservative assumptions. Follow the plans to a "T" however. In my case the plans called for #2 rebar which is very thick and can't be bent by manual rebar benders. The mason, consulting an engineering guide determined that a #3 and #4 rebar wired together provided 25% greater strength than a #2 by itself. The guide he referenced was the standard in the industry. When the inspecter saw this, even after agreeing with the 25% greater strength recommendation by the guide, refused to approve it because the plan said "#2 rebar" and advised that if we wanted to use the #3 and #4 tied together we would have to get our own engineering . . . DESPITE it being stronger and despite the inspecter acknowledging it was stronger. The mason then had to order custom bent #2 which he then wired to the #3 and #4 already in the footing. In short . . . I think my retaining wall footing could hold back Mt. Everest at this point. Lesson is . . . 1) use the standard plans they are free and are prepared by engineers, 2) get a soils report from the builder if you can, 3) make sure you follow the plans exactly. Best decision I made in my landscaping was to do the retaining walls. Practically doubled the size of my backyard.

One correction to my earlier post. The link was for retaining walls with "level backfill." I think you are doing it into a slope which would be "sloping backfill." The plans for that wall are here http://www.sandiego.gov/development-serv.... Again it only goes to 6ft. My wall is 7ft but is governed by the county and not the city. I know when I built the wall in 2002 the standard plans allowed walls up to 7ft.

4s - just sent you a private message.