Once you notice a crack, a sloping floor or a door that won’t close, it’s natural to wonder whether it’s safe to keep living here. The straight answer is that no article, photo or phone call can tell you. Whether a particular house is safe to occupy depends on what’s actually happening in that structure, and that takes someone looking at it in person.
What this post can do is help you think about the question calmly. It covers what California and City of San Diego codes treat as structural hazards, the difference between leaving, closing off part of the house and staying while you get answers, and who can actually make the call. It’s written for homeowners in La Jolla citywide, and it isn’t a substitute for a licensed structural engineer or the City’s building department.
Not every foundation problem is an emergency, but some are
Some foundation issues develop slowly: hairline cracks, a floor that has sloped a little over years, doors that stick in some seasons. Those deserve attention and a proper look, but they don’t necessarily mean anyone has to move out tonight. Other situations are different, and a few are urgent.
We can’t give you a crack width, a slope or a gap size that separates fine from dangerous. None of the official sources we reviewed sets a threshold like that for homeowners, and we won’t invent one. Size matters less than what’s causing the problem, whether it’s getting worse, and what part of the structure it affects. A HUD inspection guide puts it simply: “Cracks should always be evaluated to determine their cause and whether corrective action is required.”
What the codes treat as hazards
It helps to know the language officials use. California Health & Safety Code §17920.3 lists conditions that make a building substandard when they exist “to an extent that endangers the life, limb, health, property, safety, or welfare of the occupants.” Its structural hazards include:
- “Deteriorated or inadequate foundations.”
- “Defective or deteriorated flooring or floor supports.”
- “Members of walls, partitions, or other vertical supports that split, lean, list, or buckle due to defective material or deterioration.”
- “Members of ceilings, roofs, ceiling and roof supports, or other horizontal members that sag, split, or buckle due to defective material or deterioration.”
- “Fireplaces or chimneys that list, bulge, or settle due to defective material or deterioration.”
The San Diego Municipal Code addresses the most serious cases directly. It describes a dangerous structure as one that “has collapsed, has partially collapsed, has moved off its foundation, or lacks the necessary support of the ground.” It treats a structure as unsafe when a portion “is likely to partially or completely collapse because of dilapidation, deterioration, or decay; faulty construction; the removal, movement, or instability of any portion of the ground necessary to support the building; the deterioration, decay, or inadequacy of its foundation; or any other cause.” Under the code, it’s “The City Manager or designated official” who may make those findings, not homeowners, contractors or websites. When the City does find a building unsafe, the posted notice reads “DO NOT ENTER” and “UNSAFE TO OCCUPY”.
We quote these to show how officials frame the question, not to help you classify your own house. This isn’t legal advice.
Three different answers: leave, close off an area, or stay and get it looked at
Building safety isn’t always all-or-nothing. Post-earthquake guidance from the Applied Technology Council (ATC-20-2) is written for damaged buildings, but one of its ideas applies more widely: “Localized structural damage may place a portion of a building in an unsafe condition while other areas remain usable.” Its restricted-use category exists for cases “where a clearly unsafe condition does not exist but the observed damage precludes unrestricted occupancy.”
That gives three rough paths. Which one fits your house is for a professional on site to say.
Leave and keep people out. Get everyone out and call for help if you see signs like these: the house has shifted or moved off its foundation, a floor, ceiling, stair or deck is sagging or giving way, a chimney or wall is leaning or coming apart, or doors and windows have jammed suddenly alongside new cracks. The same applies if there’s a gas smell, damaged wiring near the movement, or ground that has slid or opened near the house. ATC-20-2 says that when damage is substantial, “do not wait for an official evaluation of the building.” Ready.gov’s line is simple: “Do not enter damaged buildings.” If anyone is hurt or in danger, call 9-1-1.
Close off an area until it’s looked at. If the concern is limited to one place, such as a sagging section of floor, a deck or porch pulling away, or a room where the cracking is concentrated, it can make sense to keep people and heavy furniture out of that spot until a professional has seen it. This is a precaution, not a finding that the rest of the house is fine.
Stay, watch and schedule an evaluation. If the signs are older and slow-moving and nothing has changed suddenly, you may be able to stay while you arrange an evaluation. Ask whoever evaluates the house to confirm that. Use the time to document. Photograph cracks with something for scale, date the photos and note any doors that start sticking. Our guide to crack monitoring with telltales and photos shows a simple method. The HUD guide notes that “A clean crack indicates recent movement; a dirty or previously filled crack may be inactive”, which is the kind of detail worth photographing and pointing out to whoever comes.
If you’re seeing several things change at once, such as floors, doors and new cracks, our post on early signs of a sinking foundation explains why progression matters more than any single sign.
Who can actually decide
- A licensed civil or structural engineer you hire can evaluate the structure, explain the cause and tell you in writing what they recommend, including whether to restrict use. If you’re not sure when to bring one in, see when to involve a structural engineer and our structural engineer page.
- The City of San Diego’s building officials decide whether a structure is legally unsafe or dangerous and can post it. After a disaster, ATC-20-2 notes that “The jurisdiction will usually allow the entry and occupancy of a building to be determined by a design professional engaged by the owner, if their written and signed occupancy recommendations appear reasonable and are posted on the building.”
- A geotechnical engineer may be needed when the problem is the ground itself, such as a slope, fill or soil movement under the house.
- A foundation contractor like us can document what’s visible and explain repair options, but we don’t make occupancy or safety determinations.
If you rent, your situation has its own rules. See our post on foundation problems in rental properties for what to document.
While you wait for answers
- Keep notes and dated photos of every crack, gap and sticking door.
- Watch for change, especially after heavy rain or an earthquake.
- Don’t patch or paint over cracks before someone has seen them.
- Keep water away from the foundation: clear gutters and downspouts and fix leaks.
- Don’t put heavy loads, like a filled bookcase or a hot tub, on an area you’re worried about.
- If something changes suddenly, treat it as the first path above: leave and keep people out.
A foundation inspection or broader structural inspection records what’s visible today, and our foundation cracks and sinking foundation pages explain how those issues are approached.
Who answers which question
- Is my house safe to live in? A licensed structural or civil engineer on site, or the City’s building officials. Not a website, a photo review or a contractor’s opinion.
- What’s causing this? An engineer, sometimes with a geotechnical engineer for soil and slope questions.
- What would repair involve? The engineer’s recommendations, then contractors pricing that scope.
- What should I write down now? You can start today with photos and notes.
Cost factors, not prices
We don’t publish repair prices, because they depend on the house. The things that drive scope and cost include the cause of the movement, whether an engineer’s evaluation and plans are needed, whether permits are required, the foundation type (raised or slab), access to the crawl space or slab, the slope and soil on the lot, drainage work that may need to come first, and whether you need to limit use of part of the house during repairs.
Where we fit
We’re a foundation and structural repair company serving La Jolla citywide. We can visit, document the cracks, slope and movement we see, and explain it in plain terms so your conversation with an engineer or the City starts with good information. We aren’t engineers or building officials, and we don’t decide whether a house is safe to occupy. We work with verified contractors and coordinate with licensed engineers as needed. This post is general education, not an assessment of any property.
Next step
If you’re living with foundation concerns and want them documented, request a Free Quote for an on-site visit anywhere in La Jolla, or call (650) 739-6537. If something has changed suddenly or anyone is in danger, leave the house and call 9-1-1 first.
Sources (accessed October 28, 2026)
- California Health & Safety Code §17920.3 (substandard buildings), via California.Public.Law
- City of San Diego Municipal Code, Chapter 12, Article 1, Division 4 (dangerous, unsafe and substandard structures)
- Applied Technology Council, ATC-20-2 Appendix A, Guidance for Owners and Occupants of Damaged Buildings (1995)
- Applied Technology Council, ATC-20 Post-Earthquake Safety Evaluation of Buildings
- Ready.gov (FEMA), Earthquakes: After an Earthquake
- U.S. Department of Housing and Urban Development, Residential Rehabilitation Inspection Guide (2000)