Retaining walls may hold risks for hillside neighbors

Q: The side-yard retaining wall that separates our house from our uphill neighbors' house in effect holds their hill off our house. This wall predates both of us, so we don't know who put it in or if it's on the property line. It was damaged in last year's earthquake and needs repair, which this neighbor is leaving up to us. I think the cost should be shared, but I don't know. Your thoughts?

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Q: My house is located a few feet from a brick wall that, because it's on a slope, is up to 7-1/2 feet tall. It's owned by my neighbor. This wall tilts 20 degrees toward my house, has large cracks, and I'm concerned that either excessive rain or an earthquake will cause the wall to collapse onto my house.

Whose responsibility is it to monitor the wall's condition, and how can this be resolved amicably?

A: Attorney Karen Willie sees many cases involving retaining-wall problems caused by earth movement. She says homeowners are wise to resolve these issues now because meteorologists predict a wet El Niño winter, thus increasing the potential for even more problems.

Basically these cases require both of you to do two things: Decide what repairs or other action needs to be taken, and decide whose responsibility it is to pay for it.

Let's start with the second question first. Willie suggests you visit your local government's building department and research whether a permit was issued for the wall. You'll want to look under your address and your neighbor's.

What you're looking for is a building plan for the wall, any inspector's notes, "and most importantly who took the permit out." This should tell you which property claims the wall.

If there are no permits, then to know who's responsible for the wall, you must know who owns it.

In the first query, you may have to survey the boundary.

The next issue is why these walls are failing. While the reason may be natural (like an earthquake), it's often the case that the cause is manmade, Willie says. Here are some examples.

The uphill neighbor puts fill dirt behind the wall as a way to increase level yard space, and this exerts pressure on the structure. Or the downhill neighbor cuts into the base of the slope to build the wall, thereby weakening the supporting ground. Or the wall has poor drainage; water weight is causing it to bow out. Or perhaps the cause is poor design.

"In buying a house, if someone says something is a retaining wall, that doesn't mean it is," cautions Willie, who estimates that two out of three "retaining" walls she encounters in her practice weren't structurally designed for that job.

The best way to discover why the wall is failing is to hire a geotechnical engineer, whose task will be to pinpoint the problem and design a fix. Then "the person who built the wall usually has maintenance responsibility under the law," Willie says.

But before launching in, she suggests that if the uphill neighbor owns the wall, this neighbor might see if a homeowner's-insurance policy might pick up part of the tab. The thinking here: that a failing wall exposes the owner to liability resulting from damage to the downhill neighbor's property.

Q: I bought a Seattle house two years ago that has a 10-foot-wide driveway with an easement between three houses. One neighbor says he's building a carport. How close to the easement and my driveway can he come?

A: Questions about zoning and building codes can be answered by your local municipality's land-use department.

In Seattle, that's the Department of Design, Construction and Land Use. According to DCLU spokesman Alan Justad, in single-family-home areas, open, detached carports must be three feet from the side or rear property line.

The roof can extend one foot farther toward your property.

If you feel this response doesn't adequately address your situation, call the DCLU at 206-684-8850 or go online to www.ci.seattle.wa.us/dclu where you'll find a list of contacts and phone numbers.

Home Forum answers readers' real-estate questions. Send questions to Home Forum, Seattle Times, P.O. Box 1845, Seattle, WA 98111, or call 206-464-8510 to leave a question on a recorded line. The e-mail address is erhodes@seattletimes.com. Sorry, no personal replies. More columns at www.seattletimes.com/columnists.