Do You Need a Survey for an ADU? Bay Area Requirements by City

Planning an ADU in the East Bay? Somewhere between your first sketch and an accepted permit application sits a question every homeowner eventually asks: do I actually need a survey for this? The honest answer is "it depends on your city and your lot" — so we pulled the actual ADU submittal checklists from East Bay planning departments and read them. This guide reports what the documents really say, city by city.

What State Law Requires (and What It Leaves to Your City)

California's ADU statutes (Government Code §66310 and following) make ADU approval ministerial: no public hearing, a decision within 60 days of a complete application, and it's "deemed approved" if the city misses the deadline. A detached ADU up to 800 square feet and 16 feet tall with 4-foot side and rear setbacks must be approved regardless of local standards like lot coverage.

But state law governs what standards apply — not how you prove compliance. Cities remain free to decide what a complete application looks like, and every East Bay checklist starts with a site plan drawn to scale showing property lines with dimensions, existing structures, setback distances, and usually easements, utilities, and trees. Several go further and require a survey by a licensed land surveyor in specific, written-down situations.

One more wrinkle worth knowing: the 4-foot setback that makes most ADU sites work is measured from your legal property line — and in East Bay neighborhoods platted a century ago, the fence is routinely a foot or more off that line. Design tight to a fence line and the error surfaces at the worst possible time. (More on that in our fence survey guide.)

The Four Triggers That Make a Survey Required

Across every checklist we reviewed, survey requirements cluster around four situations:

• Building near a property line. The closer your ADU sits to the line, the more likely the city wants the line professionally established — and 4-foot setbacks are close.
• Sloped lots. Hillside parcels trigger topographic requirements: contours, cross-sections, grading plans.
• New detached construction. Some cities require a survey for any new structure, full stop.
• Flood zones. Parcels in FEMA flood zones can trigger elevation certificates — a licensed-surveyor product.

City-by-City: What the Checklists Actually Say

Oakland — the strongest survey triggers in the East Bay

Oakland's ADU application spells it out. A line and/or topographic survey — prepared by a California licensed land surveyor, wet-stamped, no more than 3 years old — is required when any new or replacement footprint comes within 3 feet of a property line, or when the lot slopes 20% or more (a huge share of the Oakland hills). At the building-permit stage, a boundary survey is required if the structure appears within 10 feet of a property line — which describes nearly every 4-foot-setback ADU. Sloped lots also need existing and proposed contours, cross-sections, and a grading plan if any grading is proposed, and trees (including neighbors' trees within 10 feet of construction) must be mapped with trunk diameters.

Berkeley — a survey for all new construction

Berkeley's building-permit checklist for one- and two-family dwellings lists a survey requirement for "all new construction" — meaning every new detached ADU — plus additions within 1 foot of a property line, additions within 6 feet without fire-resistive construction, and even new windows within 4 feet of a line. In the Hillside Overlay ("-H") district, zoning applications require a wet-stamped boundary/topography survey no more than 5 years old with contour lines, and grading over 50 cubic yards needs a grading plan. Berkeley also caps hillside ADUs smaller (850–1,000 sq ft) than the citywide 1,200.

Piedmont — a full site survey on every application

Piedmont's ADU checklist makes a site survey the first required plan item for every application: lot-line dimensions and coordinates, grade elevations at building corners, floor, eave, and roof-peak elevations, utilities, easements, and contour lines at 2-foot intervals. That's a combined boundary-and-topographic survey in everything but name — on every Piedmont ADU.

Albany — surveyor certification before the foundation pour

Albany allows rear and side setbacks of just 3 feet — more permissive than state law — but any new detached ADU closer than 4 feet to a property line requires a form certification by a licensed surveyor before the foundation is poured. Properties near Cerrito or Codornices Creeks may also face Watercourse Overlay (FEMA) rules.

Fremont — boundary survey within 24 inches of a setback

Fremont publishes the clearest rule in the county: a boundary survey is required for any project building outside established building lines and within 24 inches of a minimum setback — which a 4-foot-setback ADU almost always is. Fremont also requires trees 6-inch diameter and larger to be located on the plan by a licensed surveyor, a preliminary title report for new floor area, and a setback/pad elevation certificate when construction is near a property line.

Alameda, San Leandro & the flood-zone cities

The island city of Alameda reserves the right to request "a property survey or title report" and runs a special FEMA height-exception regime for detached ADUs in Special Flood Hazard Areas. San Leandro requires an elevation certificate for parcels in the 100-year floodplain and a soils report for new detached structures in liquefaction or landslide zones. Dublin's checklist requires two elevation certificates for properties in FEMA A, AE, or AO zones.

Pleasanton — 1-foot contours for detached ADUs

Pleasanton's plot-plan checklist for detached ADUs calls for topographic lines drawn to 1-foot contours, anticipated earthwork quantities, and drainage flow arrows — a topographic survey scope, spelled out in the checklist — plus a preliminary title report on every application.

Lafayette, Orinda & Moraga — Lamorinda's terrain writes the rules

Lafayette requires a certified survey for development encroaching within 5 feet of required setbacks — and since ADUs are designed to 4-foot setbacks, that catches nearly every new detached unit. Site plans must be prepared on that survey, with a title report for every ADU class, topography at 2-foot contours, surveyed native trees 12 inches and up, and creek setbacks shown in plan and section. Orinda wants property lines dimensioned in metes and bounds, contours and cross-sections on slopes over 20%, and drainage-plan topography "based on a topographic survey" (triggered by as little as 500 sq ft of new impervious surface). Moraga requires existing topography and proposed grading on every ADU site plan, plus adjacent building heights and creeks with widths. All three cities issue building permits through Contra Costa County, whose geotechnical triggers apply on top.

Concord & Martinez — surveyor-based plans and low topo thresholds

Concord's plan-review checklist says it plainly: site plan information "should be based on a survey prepared by a licensed surveyor." The engineering side adds finish-grade elevations at building corners, lot corner and high-point elevations, drainage arrows, profiles extending 20 feet into adjacent lots — and 2-foot contours on hill-site lots. Martinez requires lot dimensions in metes and bounds, a title report, and topography with 2-foot contours once the lot has more than 5 feet of elevation difference — a threshold most Martinez lots outside downtown cross easily.

Walnut Creek & unincorporated Contra Costa — slope-triggered geotech

Walnut Creek's ADU bulletin requires property lines, all easements, and every tree with its dripline (including neighbors' trees overhanging your lot), with a soils report required when slopes exceed roughly 33% or the site has a history of creep or settlement. Unincorporated Contra Costa County — which covers Alamo, El Sobrante, Kensington, Rodeo, and Crockett, and provides building services to Lafayette, Orinda, Moraga, and Hercules — can require a geotechnical report when the site slopes more than 5% (just one foot of fall across the ADU footprint), with exemptions only below 25% slope on trouble-free soil.

Vallejo & Benicia — the Carquinez corridor

Vallejo names boundary and topographic surveys as checklist items the Planning Division can require case by case — the boundary survey "prepared by a licensed California Surveyor" — and its ADU guide says a soils report is generally required for all new construction. The standout rule: citywide, the lowest finished residential floor must sit at or above 13.50 feet NAVD88 (FEMA's 10-foot base flood elevation plus 3.5 feet for sea-level rise) — a question only surveyed elevations answer. Benicia asks for plot plans with metes-and-bounds lot dimensions, trees with species and trunk sizes, and contours on lots with more than 5 feet of elevation difference, with special design standards in the Downtown and Arsenal Historic Districts.

Richmond, El Cerrito, Pleasant Hill, Hayward & the rest — site plan yes, survey discretionary

Not every city writes a hard survey trigger. Richmond, Hayward, Livermore, Pleasant Hill, Antioch, Pittsburg, and Pinole require scaled site plans with property lines, setbacks, and easements, but name no surveyor requirement — while reserving the right to request more. El Cerrito lists "Site Survey. Conducted by licensed surveyor" as an as-needed item along with a recent title report. San Pablo says the quiet part out loud: its site plan handout requires metes-and-bounds lot lines and states that "if property lines and structure locations are not known, a professional survey of the site may be required" — plus a geotech report for all development east of I-80. One Pleasant Hill wrinkle worth knowing: setbacks there are measured from the furthest projection — the eave — to the property line, which shrinks your real margin. In these cities the survey question comes down to your lot: if you're designing to a 4-foot setback off an unverified fence line, the risk is yours either way.

Quick Reference: Survey Triggers by City

Requirements verified against each city's published ADU submittal checklist as of August 2026. Cities revise checklists — we confirm current requirements with the jurisdiction at the start of every project.

Even Where No Survey Is "Required"

Here's the part the checklists don't tell you: the building inspector holds a survey card of their own. When foundation forms go up 4 feet off a property line, field inspectors frequently require a licensed surveyor to verify the forms conform to the approved plans before signing off on the pour — regardless of whether the submittal checklist ever mentioned a survey. Some cities have simply written the practice down: Albany requires surveyor form certification before the foundation pour, and Fremont requires a setback/pad elevation certificate when construction is near a property line. In cities that haven't, the requirement arrives as an inspector's correction — mid-project, with the concrete truck scheduled and no boundary established to verify against. A surveyor starting from zero at that point has to do the full boundary research and fieldwork anyway, on a rush timeline. If the survey existed from day one, form verification is a short return visit.

Which is the practical bottom line of everything above: if you're building an ADU, it's in your interest to start with a comprehensive survey — it feeds your design team accurate lines and grades, satisfies whatever your checklist demands, and has the verification infrastructure already in place when the inspector asks. Three more reasons homeowners order one even where no checklist requires it:

• The setback is measured from the legal line. A 4-foot setback designed off a fence that's 18 inches inside your line means your finished ADU encroaches — discovered at final inspection, or when the neighbor sells and their buyer's surveyor finds it.
• Your designer needs a base map regardless. Every site plan on every checklist needs property line dimensions, structures, and setbacks. A surveyor-prepared DWG base map is measured data instead of assembled guesswork.
• Slopes and drainage don't care about checklists. Grading, retaining walls, and foundation design on any sloped East Bay lot need real contours — and plan checkers in the hills know measured topo from traced parcel maps.

What an ADU Survey Costs

Most East Bay ADU site-plan surveys — boundary verification plus topographic mapping on a residential lot — run roughly $1,500 to $3,500 depending on lot size, slope, vegetation, and how much boundary research the neighborhood requires. Against a $150,000–$400,000 ADU build, it's one of the smallest line items in the project — and the only one that prevents the catastrophic version of a setback mistake. Full pricing context in our Bay Area survey cost guide.

How We Handle ADU Surveys

Our ADU survey service starts with your city's checklist and scopes to it: boundary research and monument recovery, one laser-scanned site visit capturing structures, trees, utilities, and terrain, then a stamped site-plan base map with staked property corners — plus 1-foot contours, drainage data, or elevation certificates where your city or lot demands them. Your designer gets a layered DWG to draw on directly; your application gets accepted the first time.

Send us your address and city and we'll tell you exactly what your checklist requires — before you've spent a dollar on design.