Land surveyors in Los Angeles: licensed Professional Land Surveyors, quoted

This is the most consequential LA-only fact on this page, and it surprises most homeowners. In City of Los Angeles hillside areas governed by the Baseline Hillside Ordinance (Ordinance No. 181624, codified at LAMC section 12.21 C.10), your Maximum Residential Floor Area is not a flat number. It is computed from how much of your lot falls into each slope band, and the code requires that calculation to rest on a Slope Analysis Map "prepared, stamped, and signed by a registered civil engineer or licensed land surveyor," based on a survey of the natural and existing topography.

The ordinance is specific about the document. The map must be at a scale of not less than 1 inch to 100 feet, with a contour interval of not more than 10 feet with two-foot intermediates, must state the datum, source and scale of the topographic data, must delineate each slope band with contrasting colors or hatching, and must tabulate the area in each band. The Director of Planning must verify it was prepared by a registered civil engineer or licensed land surveyor, and must approve the resulting floor area calculation before you can even apply to the Department of Building and Safety for a permit.

The practical consequence: in Hollywood Hills, Silver Lake, Echo Park, Mount Washington, Bel Air, Brentwood and the Baldwin Hills, a topographic survey is not paperwork you can skip or estimate. It is the input that determines the square footage you are legally permitted to build, and it sits on the critical path before Building and Safety will look at your project. Getting it done early, and done right, is the difference between a design that gets approved and a redesign.

Grading is the companion requirement. Under LAMC section 91.7006, grading plans must be prepared and signed by an individual licensed by the State and must show property limits and accurate contours of existing ground, proposed finish contours, top and toe of cuts and fills, and structures on adjacent property within 15 feet. Note the precise wording, because it matters: the Department may require plans to be prepared by a licensed surveyor when the property location and its limits are not clear. That is may, not shall. Grading involving more than 5,000 cubic yards of cut or fill also triggers soils and geology reports.

No. California law does not require a survey to buy or sell a home, and neither the City nor the County of Los Angeles adds one. California closings run on title insurance and escrow. When a survey does get ordered at a purchase, it is because a lender or title insurer wants to remove the standard survey exception from the policy, which otherwise excepts any state of facts an accurate survey and inspection of the land would show. That is an underwriting condition and a negotiable one, not a legal requirement.

The requirement that genuinely does bite is different, and more important. Under the Subdivision Map Act, Government Code section 66499.30, no one may sell, lease or finance a parcel, or begin construction for sale or lease on it, until the required final map or parcel map has been recorded. The question is not "was this lot surveyed," it is "was this lot lawfully created." In a county with a century of uneven subdivision practice layered over Mexican-era rancho grants, that is not academic. If a parcel's legality is uncertain, a licensed surveyor is the professional who researches it and pursues a certificate of compliance.

A related warning, and this one comes straight from the county. The LA County Assessor states that Assessor Maps are prepared for assessment purposes only, show information as recorded rather than as obtained from an independent onsite survey, and are NOT surveys, and as such should not be used in either defining property lines or in resolving disputes between neighbors. If you are about to build a fence off a parcel map you found on a county or commercial mapping site, that sentence is the county telling you not to.

One more myth to retire: an ADU permit in Los Angeles does not require a boundary survey. LADBS and LA County Regional Planning require a plot plan or site plan, not a licensed survey. What is true is that state ADU law (recodified into Government Code sections 66310 to 66342 by SB 477, effective March 25, 2024) sets hard objective dimensions measured from the property line, including four-foot side and rear setbacks for a detached new-construction ADU. Windows, doors and eaves carry their own tight clearances in LA County. Those are unforgiving numbers, so if you are unsure where your line actually runs, a survey is cheap insurance against a correction notice or an encroachment, even though nobody is requiring it.