You’ve decided to have someone look at your house for earthquake weak spots. Maybe a home inspector flagged “no visible anchor bolts.” Maybe you’re buying, selling, or renewing earthquake insurance. Maybe you just looked under the house and didn’t like what you saw.
A little preparation makes the visit more useful. The evaluator sees more of the house, you get better answers, and the written result is something you can act on. This post walks through what to gather, what to clear, what to look at yourself, and what to ask. Our seismic retrofit page covers the work itself, and our raised foundation repair page covers the foundation problems that can turn up during the same visit. If you’re still sorting out which of those two jobs you need, start with the companion post on seismic retrofit vs foundation repair.
A seismic evaluation is only as good as what the evaluator can see and what you can tell them. Know which kind of evaluation you booked, gather the house’s paper history, clear the path to the crawl space and perimeter walls, and ask for findings in writing.
Know which kind of evaluation you’re getting
“Seismic evaluation” can mean several different things. They aren’t interchangeable.
- A retrofit evaluation for a bid. A contractor looks at the crawl space to see whether the house fits Chapter A3 of the California Existing Building Code (the state’s prescriptive standard for anchoring and bracing older wood-frame houses, adopted by the City under SDMC §1411.0107) or a standard plan set, and prices the work.
- An engineering evaluation. Required when the house falls outside Chapter A3. The code sends cripple walls over 4 feet, houses with poles or columns embedded in the ground, slab portions, and conditions the building official finds beyond prescriptive scope to “a registered design professional” (CEBC §A301.2). CRMP adds sloped lots and stepped crawl-space walls to that list.
- A retrofit verification for insurance. If a retrofit was already done, the California Earthquake Authority’s Dwelling Retrofit Verification form must be signed by a licensed contractor or a civil or structural engineer. Where cripple walls exceed 4 feet, CEA requires a California registered civil or structural engineer to do that inspection (with an exception for one FEMA plan set).
- A graded assessment. FEMA’s P-50 method scores a house and assigns a Seismic Performance Grade from A to D. “An A grade is most desirable, and a D grade is least desirable.”
Ask which one you’re getting before the appointment. For the broader list of what “foundation inspection” can mean, see our post on what a foundation inspection covers.
Gather the paper history
The house’s records answer questions the crawl space can’t.
Year built. Two California programs draw a line at 1980. CRMP’s Earthquake Brace + Bolt retrofit “is only done on wood-framed, pre-1980 homes with a raised foundation,” and CEA’s verification checklist starts with “The dwelling was built prior to 1980.” Year built isn’t proof of anything, but the evaluator will ask.
Permit history. The City of San Diego lets anyone research permits and applications “from 2003 to present for any City of San Diego address” through OpenDSD, Permit Finder, and Accela. Archived building records and plans are reviewed by appointment, and the City says requests to view or obtain building plans “require an in-person appointment with a team member.” For properties built before 1955, the City directs you to the County Assessor’s Office. Two caveats from the City itself: “Not all types of property records may be available,” and plans stamped by an architect or engineer are copyrighted, so copying them requires that professional’s permission.
Earlier retrofit paperwork. If the house was retrofitted, find the permit, the plan set used, and any Earthquake Brace + Bolt verification number. CEA accepts a valid Brace + Bolt verification number on its verification form.
Prior reports. Home inspection reports, engineer letters, and pest reports can mention anchor bolts, decay, or crawl-space conditions. Copy the exact sentences. Our seller documentation checklist covers the wider set of disclosure documents.
What you know about remodels. A wall removed downstairs, a converted garage, a room added on a slab, a chimney taken down. These change how the house behaves, and some of them may not be in City records.
Clear the way
The evaluator needs to see the perimeter of the crawl space, not just the area near the hatch.
- Crawl-space access. Make sure the hatch opens and the first few feet are clear. Our post on the raised foundation repair process covers access in more detail.
- Perimeter walls. Stored items stacked against the foundation hide the sill, anchors, and cripple walls. Move what you can.
- Finished walls. If a basement or lower room has drywall or paneling over the perimeter walls, say so in advance. CEA’s verification rules allow spot checks through the finish when sheathing or anchors can’t be seen, at a minimum of two locations along each perimeter wall. Decide ahead of time whether you’re comfortable with that.
- Water heater, gas meter, chimney. Make sure these can be reached and seen. FEMA P-50’s checklist includes all three.
- Pets and people. Someone will be crawling under the house and walking the exterior.
Look before they arrive (from the hatch, not the crawl)
You don’t need to crawl in. A flashlight from the access opening and a walk around the outside answer several useful questions. Don’t enter a crawl space that is wet, tight, or has exposed wiring.
- Does the wood floor framing sit directly on a concrete wall, or on short wood stud walls (cripple walls) standing on the concrete?
- Can you see bolt heads with washers, or metal plates, along the wood sill on top of the concrete?
- Do any short stud walls have plywood or OSB sheets nailed to them?
- At the perimeter, is there a continuous concrete wall, or posts standing on separate pads?
- Do the walls step up or get taller toward the downhill side?
- Is the water heater strapped to the wall?
- Is there a brick or block chimney, and does it rise well above the roof?
- Is there a garage with living space above it, where the garage door takes up most of the front wall?
Write down what you see and take photos. You’re not diagnosing anything. You’re giving the evaluator a head start and noting what to ask about.
What the evaluator will look at
Every evaluator works a little differently, but FEMA P-50 gives a good map of the ground they cover. Its assessment form is organized into “Section A: Foundation systems, Section B: Superstructure framing and configuration, Section C: General condition assessment, Section D: Nonstructural elements, age, and size, and Section E: Local site conditions,” followed by seismic hazards and a grade.
Within those sections, these items are worth preparing for:
- Anchorage and bracing. Whether the sill is connected to the foundation and cripple walls are braced. Chapter A3 lists unanchored sills and unbraced cripple walls among its six “structural weaknesses,” along with four foundation conditions (CEBC §A303.1).
- Garage walls. P-50 notes that “it is common for the garage door opening to take up most of the wall length, often leaving narrow wall piers at each side of the opening as the only earthquake bracing,” and that the vulnerability “is particularly true where a second floor occurs over the garage.” Our post on soft-story seismic concepts covers that condition.
- Framing alterations. P-50 asks whether underfloor framing has been cut or notched “for electrical, plumbing, mechanical equipment” in ways that would affect earthquake performance.
- Chimneys. “Unreinforced masonry chimneys, in particular, have been a major source of damage in previous moderate to major earthquakes,” according to P-50. CRMP states that chimneys built before January 1, 1995 “are more susceptible to collapse during an earthquake.” Our post on stair-step and horizontal crack patterns covers chimney cracks.
- Water heater. State law requires existing residential water heaters to be “braced, anchored, or strapped to resist falling or horizontal displacement due to earthquake motion” (Health and Safety Code §19211, as quoted by CEA).
- Gas shutoff. P-50 scores whether an earthquake-activated gas shutoff valve is installed, and advises homeowners to “check with the local building department and gas company to see if gas shut-off valves are allowed.”
- Site conditions. Slope, fill, settlement, and drainage. For the map homework on your lot, see our coastal lot checklist.
Questions to ask during the visit
- Does the house fit Chapter A3 or an accepted standard plan set, or does it need engineered design? Why?
- Which of the Chapter A3 weaknesses did you find, and where?
- Is any foundation repair needed before or as part of the retrofit?
- What is outside the scope you’re looking at: chimney, garage walls, hillside conditions, rooms over the garage?
- What couldn’t you see, and what would it take to see it?
- Will the work be permitted and inspected? Chapter A3 work is “subject to inspection by the code official” (CEBC §A304.5).
If the answers point toward engineered design, our post on when to involve a structural engineer explains who does what. Before you hire any contractor, check the license on the Contractors State License Board website.
What you should get back
A useful result is in writing and names things. It should list the vulnerabilities found, where they are, the recommended path (prescriptive, standard plan, or engineered), what was out of scope, and what couldn’t be observed.
Read any grade or verification for what it is. FEMA cautions that the performance implied by a P-50 grade “could vary widely,” depending on the house, the soil, distance to the earthquake source, and secondary hazards such as liquefaction and landslide. CEA’s verification form is narrower still: it “does not cover any other seismic deficiencies other than sill bolting, cripple wall bracing, and water-heater bracing,” and the signer is not “certifying or warranting the expected seismic performance” of the house. No evaluation turns a house earthquake-proof on paper.
Cost factors, not prices
We don’t publish prices. What changes the scope of a seismic evaluation: how much of the crawl space can be reached, whether finished walls hide the perimeter, whether the house fits Chapter A3 or needs engineering, slope and stepped walls, a chimney or garage condition that adds items to review, whether foundation problems need to be assessed at the same time, and whether the result has to support a permit, an insurer, or an escrow.
Where we fit
We look at raised foundations and seismic connections in the same visit, so foundation problems and missing anchorage show up in one set of findings. Our structural inspection page describes that work. When a house falls outside Chapter A3 or needs a stamped design, we coordinate with licensed engineers as needed; our structural engineer page explains how. For hillside lots, see hillside foundation repair. This post is general education, not engineering or legal advice, and it isn’t a determination about any specific house, insurance discount, or grant.
Next step
Gather what you have, clear the hatch, take a few photos, and request a Free Quote for a seismic evaluation anywhere in La Jolla. You can also call (650) 739-6537 to talk through what you’ve found.
Sources (accessed October 17, 2026)
- FEMA P-50, Simplified Seismic Assessment of Detached, Single-Family, Wood-Frame Dwellings (May 2012)
- California Earthquake Authority, Dwelling Retrofit Verification Requirements (effective July 2019) and Get a Discount
- California Residential Mitigation Program, Earthquake Brace + Bolt Retrofit, Raised Foundation House Retrofit, and Chimneys & Fireplaces
- 2025 California Existing Building Code, Appendix Chapter A3, Sections A301.2, A303.1, and A304.5
- San Diego Municipal Code §1411.0107
- City of San Diego Development Services, Records and Procedure for Requesting Duplication of Architectural Building Plans
- California Health and Safety Code §19211 (as quoted in CEA’s Dwelling Retrofit Verification Requirements)
- Contractors State License Board, license check