How to earthquake-proof your homeNovember 20, 2008
It’s official: we just got our seismic retrofit rebate check in the mail, which means we’re 100 percent done with our earthquake retrofit! If you live in earthquake country, you’ve probably contemplated or undertaken a retrofit. Our city has a special program that provides a rebate to new homeowners who take on this project in the first year they own the house, so we decided to take advantage of that and jump right in. A year later—what a ride! Thought I’d take a minute to document the process for anyone thinking of going down this road. (Some of this info is Bay Area-specific, but much of it applies to any foundation-related project.)
Why not just buy earthquake insurance? We did all sorts of research on this. First, earthquake insurance is a scam (there, I said it!) Okay, not quite a scam, but basically the scenario in which you benefit from having insurance is a moderate quake that damages your house, but not many other houses near you. Then you get paid nicely. However, if lots of homes are damaged, you get paid less; if it’s the Big One, there’s a clause that says the state is not obligated to pay you anything at all, because they would be wiped out. So you’re basically insuring against that smallish quake. Thing is, that’s also the easiest kind of quake to prepare your home for structurally. The point of the retrofit is primarily to keep your house from sliding off of your foundation, and to keep the joists and the floorboards attached. For most houses, this means adding bolts, blocks, and plywood shearwalls to your existing foundation.
Prepare for your retrofit
First things first: get a permit. It’s not essential to get a permit for some projects, but foundation-related work is not in that category—and the permit may be cheaper than you think. (Ours cost $250, and getting it enabled us to qualify for a rebate that paid for a third of the project cost.) You can apply for the permit before you choose your contractor, or you can wait and have your contractor apply for it. We applied on our own and transferred it to our contractor after we hired him.
Figure out how to pay for your retrofit
With concern about the Big One growing across California, many communities now have programs to facilitate seismic retrofits. In Oakland, there’s a fixed fee of $250 for retrofit permits, and if you have a modest home on a flat lot, there are ready-made, pre-approved plans for you to use. (Sorry, Montclarions—the flatlanders win this round!) Other cities may have other types of incentives.
If you’re a new homeowner, find out if your community has a rebate program for seismic upgrades on newly-purchased homes. For instance, the cities of Oakland and Berkeley both have transfer tax rebate programs to encourage retrofits, and low-income homeowners may be eligible for federal funds. Also make sure you’re clear on the rules of the game. In Berkeley, for instance, your work must be completed within one year of the purchase date, whereas in Oakland, the clock starts ticking when your permit is approved, which can give you 20 months or more to finish the work. (Oakland does, however, have a strictly-enforced deadline for applying for the permit within the first 60 days of owning the home. From that point, you have 180 days to finalize your plan and get the permit approved or pay for extensions if needed.) Also consider whether the rebate amount is enough to offset the cost of any additional work required by the rebate program. (A contractor may recommend a partial retrofit, for example, which would cost a lot less than a full retrofit—but the rebate program might apply only to full retrofits.)
A retrofit costs a lot…
A lot! At least, a lot more than we thought it would. In our area, retrofitting a small (1250 sq. ft.) bungalow in 2008 costs $6K-$14K, depending on who does the work and how they do it. You can reduce this cost somewhat if you can do the bolting and shearwalling yourself, but the materials themselves constitute a good chunk of that. (We were also uncomfortable doing the bolting given that you’re driving bolts directly into the foundation, though in retrospect I do wish we’d done the shearwalls ourselves.) Bear in mind that the process also generates an inordinate amount of dust, if that’s a concern.
Draw up some plans
Once you’re squared away on the cost and permit details, you’re ready to put a plan together. First, find out if your home qualifies for a ready-made retrofit plan. There are caveats to using these—they’re not perfect, and some contractors have mixed feelings on them—but using one will significantly reduce your costs, and will go a long way in protecting your home from a quake. For Bay Area folks, ABAG has a plan set for wood-framed homes that are two stories or less, have continuous concrete foundations and crawl spaces or basements, have no cripple walls over four feet high, and don’t have living space over garages.
If you don’t qualify—and we didn’t, since two of our cripple walls are six feet high—you’ll need to get a civil engineer to draw up plans for you. (In theory, there was supposed to be a “Plan Set B” that would address homes like ours, but as far as I know this has never been produced.) We actually had a lot of trouble finding a civil engineer who would charge by the hour. We knew our plans were pretty straightforward, since our house is on a relatively flat lot and met all the other Plan Set A requirements, but many of the recommended engineers would only charge flat (and exorbitantly high!) rates for a retrofit plan—or worse, they wouldn’t take our piddly little job at all. If you’re not on a hill or retrofitting a complex foundation, try calling independent engineers who work locally, rather than the big firms. Some retrofitting contractors even have engineers on staff (though in the East Bay this was surprisingly rare—all we needed was that seal for the City to say okay, but none of the firms who bid on our job had anyone to provide it!) In the end, the civil engineer we used charged for under four hours. (Talk to me after the next quake and we’ll see if they were four hours well spent—but both the contractor and the City agreed with the plan, even noting that it might be overkill on the safety front.)
Choose a contractor
Talk to a number of different contractors. Different firms have different ideas on how to approach retrofitting (and on how much to charge you!), and it’s helpful to hear what each has to say. I found it useful to get a couple of bids early on in the process as we were still working with the engineer; we ended up choosing one of those early contractors in part because he had contributed so much to the plan. In our case, we had an existing retrofit that had been done in the early 90s, so some things on that had to be fixed, while others could be left. (Fortunately, the previous owners pulled a permit for it—otherwise we would have been required to rip it all out to “show” what was underneath!) However, the science of retrofitting is evolving, and some of what had been done the first time around no longer seemed wise. (Ours had been done by a firm that had a particular style such that everyone who walks into our basement—from the contractors to the city inspectors to the termite guy—says “Oh, Company X has been here!”)
If your house requires engineered plans as ours did, consider spending more on the plans themselves and then having a general contractor do the physical work, rather than hiring a firm that specializes in retrofits. It’s not rocket science, and a good contractor will probably do just as good a job. If you’ve never taken on a construction project before, you’ll probably also want to make sure you have either a civil engineer or a contractor who will see you through the permitting process. That’s also not rocket science, but it can be tedious, and we found (on this and other projects) that it was much easier to work with the City when there was a professional they knew and trusted involved in the conversation.
Get the work done
Once you get started, the actual retrofitting process doesn’t take too long. Ours was done over a two-week period with some breaks in the middle, but I know people who’ve had their homes done in just a few days. As your retrofit is being done, check the work every now and then. In our case, the workers had already overdriven the nails in most of our shearwall before we noticed. Our primary contractor was well aware that overdriving nails was bad, but he was busy and not always on the job site. (To that end, if you can get a reliable primary contractor who is on the job site regularly or is doing the work herself, that’s even better.)
Can’t afford a full retrofit?
If a full retrofit isn’t in your budget—and quite honestly, it wouldn’t have been in ours without the transfer tax rebate in the mix—you can still take small steps to improve your home’s earthquake readiness:
- Install a gas shut-off valve (ironically, this is super cheap relatively, but is the one thing we have yet to do!) They now make valves that will turn themselves off automatically in a quake, too.
- Brace your water heater. Again, easy to do with a few dollars’ worth of supplies and a free afternoon.
- Bolt into the wall any bookshelves or other furniture that could fall.
- Have your chimney reinforced to avoid collapse (though this can also get pricey).
- Make a family plan and an earthquake kit (and don’t forget dog food! Or, y’know, kid food, if you have one of those).
- ABAG’s Home Quake Safety Tool Kit
- Bay Area recommendations for retrofitters
- Retrofitting historic structures
- Seismic Retrofit Association