Easements on Site Plans: What They Mean for Your Bay Area Building Project

Easements on site plans California projects require you to show are legally binding encumbrances — not optional disclosures or administrative footnotes. They define where you can build, how close structures can approach your property lines, and whether your planned footprint actually fits within the lot's buildable area. Before your drafter lays out a single dimension on your site plan, knowing what each easement type restricts can save you from a complete redesign at plan check.

In the Bay Area, easements appear on nearly every residential and commercial lot — utility corridors cutting through backyards, shared driveway access strips along side yards, drainage channels along rear lot lines, and PG&E transmission rights-of-way that can eliminate significant portions of your buildable envelope. Each type carries different restrictions on what you can place above or below grade. Understanding those distinctions early is the difference between a smooth permit path and a project that gets flagged before structural review even starts.

The legal definition of an easement is a non-possessory right to use another person's land for a defined purpose. What matters practically is where that easement falls on your parcel, its recorded width, and which improvements — if any — are permitted within it. This post covers all of that.

Reading Easements on Site Plans: California's Most Common Types

Bay Area lots carry a surprisingly wide variety of recorded easements. Some are narrow and easy to design around. Others bisect a lot in ways that fundamentally reshape the entire project. Here's what you're most likely to encounter — and what each one means on a plan sheet.

Utility Easements

Utility easements are the most common type you'll see on a California site plan. They grant PG&E, AT&T, EBMUD, or a local water or gas district the right to install, operate, and maintain infrastructure across your property — overhead lines, underground conduit, water mains, gas services. Typical widths range from 5 feet to 20 feet, and transmission corridor easements can run wider still.

Within a utility easement, most jurisdictions prohibit permanent structures. That typically includes:

• Foundations and footings of any depth
• Retaining walls (in most configurations)
• Pools, spas, and hardscape attached to a structure
• Outbuildings and detached accessory structures

Some utility easements do permit fences, driveways, and shallow landscaping — but you'll need the utility company's written consent before building anything within the corridor, and that consent should be referenced in your permit submittal. Don't assume the plan check reviewer won't notice a footing that clips a P.U.E. by six inches.

Access and Ingress/Egress Easements

Access easements give another party — typically a neighboring property owner or a public agency — the right to cross your land. Shared driveways are the classic Bay Area example: a 10- to 12-foot strip along a side yard that two or more parcels depend on for vehicle access. Flag lots almost always carry one.

Building within or across an access easement requires written approval from the easement holder and, in most cases, a formal easement modification recorded with the county. Your permit application will stall if your site plan shows a structure encroaching on a recorded access corridor and you haven't addressed it in the submittal documents. This isn't a condition the building department can waive — it's a title issue that has to be resolved upstream.

Drainage and Storm Water Easements

Drainage easements reserve a corridor for surface or subsurface storm water flow. In hillside Bay Area neighborhoods — Berkeley Hills, Orinda, Los Gatos — these appear along the lower edges of lots and natural swales, often 10 to 25 feet wide. When a drainage easement overlaps a creek setback imposed by a local flood control district, your effective buildable area shrinks fast. You cannot fill, grade, or construct within most drainage easements without approval from both the easement holder and the relevant municipal storm water authority.

What Easements Actually Restrict — and What They Don't

This is where a lot of property owners get tripped up. Easements and setbacks are separate constraints, and conflating them leads to design errors that surface at plan check. Your zoning setbacks define how close you can build to a property line based on municipal code. An easement defines an encumbrance based on a recorded private or public right — and the two can overlap or diverge completely independently of each other.

The Building Envelope Reality

When an easement falls entirely within your setback zone, it rarely changes your practical buildable area — you were already prohibited from building there. The problem arises when an easement extends beyond the setback line and into what you believed was usable square footage. A 15-foot utility easement along a rear lot line doesn't compound with a 5-foot rear setback to give you a 15-foot restricted zone. It gives you a 15-foot restricted zone on its own terms, regardless of what the setback says.

Easements do not function as open space credits or lot coverage exemptions in most California jurisdictions. The land area within an easement counts toward your gross lot area for density and floor area ratio calculations, but you cannot build on it. For a detailed look at how encumbered land affects development calculations, see how lot coverage is calculated on a Bay Area site plan. The interaction between encumbered area and coverage limits is one of the more commonly misunderstood constraints in residential permitting.

Surface Use vs. Subsurface Rights

Not all easements restrict surface use uniformly. Some utility easements only prohibit permanent structures but permit landscaping, unattached patios, and shallow hardscape — read the recorded instrument, not just the site plan callout. Others restrict all surface improvements. Subsurface easements (buried gas lines, fiber conduit) may allow construction at specified clearances above the line, but you'll need an as-built location survey to confirm actual depth before your engineer can sign off on a footing design.

A few things easements typically do not restrict:

• Growing grass, ground cover, or shallow-rooted plants — in most cases
• Temporary surface use during construction, such as equipment staging
• Maintaining existing fences already at grade, if in place prior to the easement recording
• Underground irrigation at shallow depth, where clearance requirements are met

Read the recorded document — not just the graphic on the site plan — before assuming any of these exemptions apply. Easement language in older deeds, particularly in unincorporated county areas, can be vague or conflict with current utility practices. When in doubt, get written confirmation from the easement holder before finalizing your design.

Easement Notation on a Site Plan: From Simple Disclosures to Layered Overlays

Site plans present easements in a few consistent ways, but graphic conventions vary by drafter, jurisdiction, and how complex the title report is. Knowing how to read what's shown — and when the notation on the drawing doesn't tell the full story — is critical before you commit to a design direction.

Graphic Conventions and What They Mean

On a standard California site plan, easements appear as:

• Hatched or shaded bands dimensioned from property lines, with a text label identifying the type
• Dashed boundary lines with a callout — for example, "10' P.U.E." for Public Utility Easement
• Polygon overlays annotated with the easement type, recording instrument number, and book/page reference
• Centerline annotations for pipeline or transmission easements, with the corridor width noted on each side

The plan check reviewer will cross-reference the easement notation against your proposed footprint. If your structure encroaches — even marginally — into a hatched easement zone, you'll receive a correction request. In many Bay Area jurisdictions, easement conflicts are among the most frequent reasons permit sets get flagged at initial review. For a broader picture of what else triggers corrections, see the breakdown of common permit set rejections at Bay Area plan check.

Cross-Referencing Your Title Report

The site plan shows the easement's location. The preliminary title report — specifically Schedule B, Section II — describes its terms. You need both documents together. A "P.U.E." callout on a drawing tells you the corridor exists and where it falls. The recorded instrument tells you what the utility company can do within it, whether fencing is permitted, what surface restoration they must provide after excavating, and whether the easement is exclusive or shared.

Never rely solely on the site plan graphic to understand what's actually restricted. Easement language in older grant deeds — and Bay Area lots on older subdivisions carry some very old documents — can be ambiguous or use terminology that's since been superseded. Your drafter can accurately note the easement on the plan, but the legal interpretation is something your title company or a real estate attorney should confirm before you design hard against its edge.

If the property hasn't had a recent boundary survey, you may not know the precise location of recorded easements relative to existing improvements on the lot. This is one of the primary reasons a property survey is often required before starting a project in California — particularly when title documents reference easements without dimensioned field locations.

How Easements Shape Bay Area ADUs, Additions, and Commercial Projects

Easements don't affect every project type the same way. Where they fall on your lot determines how much of a constraint they actually are. For some project types, the interaction is more consequential than others — and knowing which category your project falls into changes how much due diligence you need before design begins.

ADUs and Accessory Structures

ADUs are typically sited toward the rear of the lot — exactly where utility and drainage easements concentrate. A 10-foot public utility easement along the rear lot line runs independently of whatever setback reduction state ADU law provides. Even if current law reduces your required rear setback to 4 feet, the utility easement still prohibits a foundation within its 10-foot width. The two constraints don't merge — the more restrictive one governs, and they measure from the same boundary.

Your ADU permit set must show all recorded easements on the site plan with dimensions from the property line. If your proposed ADU footprint conflicts with a recorded easement, the building department will not approve the permit regardless of whether the ADU otherwise qualifies under SB 9, SB 1069, or local density bonus provisions. Resolve the easement conflict at the design stage — not after you've already coordinated structural and Title 24 drawings.

Room Additions and Garage Conversions

For room additions along a side yard, access easements are the primary concern. Shared driveway easements frequently run along the exact side yard where a homeowner wants to expand. The easement doesn't make the addition impossible, but the footprint must stay clear of the easement corridor — or the easement must be formally relocated by written agreement with the holder, recorded with the county before permit submittal.

Garage conversions present a different issue. The existing garage structure may already sit partially within an easement that was overlooked at the time of original construction — a not-uncommon scenario on older Bay Area lots. When you convert a garage to habitable space, the building department may require you to verify easement clearance on the updated site plan. An encroachment that passed without comment in an uninhabited garage often draws more scrutiny when the space becomes living area subject to R occupancy standards.

Commercial Tenant Improvements

Commercial properties in the Bay Area frequently carry reciprocal parking and access easements between adjacent parcels — common in shopping centers, medical office campuses, and mixed-use infill developments. These easements affect where you can add exterior ramps, ADA accessible paths, HVAC equipment pads, and new utility connections. If your tenant improvement scope touches any site work at all, confirm easement locations before the civil or MEP drawings are finalized. A reciprocal parking easement that restricts where you can place a transformer pad will cascade into MEP coordination and potentially delay your permit timeline.

Building Your Strategy Around Easements Before Design Begins

The cleanest approach to easements is treating them as a first-order design input — not a problem you discover at plan check or after structural engineering is underway. That requires deliberate front-loading of the research phase and a clear sense of when a survey is worth ordering before conceptual design starts.

Front-Loading the Research

Before your drafter produces any design drawings, gather these documents:

• Preliminary title report with Schedule B exceptions — this lists every recorded easement, covenant, and restriction affecting the parcel
• County assessor parcel map or subdivision plat, which shows recorded easement corridors overlaid on the lot boundaries
• Any prior permit set for the property — older site plans often show easements with dimensions your current title report doesn't include
• Utility as-built records from PG&E or the local water district, particularly if you're working near older infrastructure

Pass all of this to your drafter at the initial consultation. A site plan prepared without this information may require significant revision once the title report arrives — and revisions at the conceptual stage cost far less than revisions after structural calcs are submitted. It's also worth mapping easements against your lot's coverage limits early. If a drainage easement consumes 700 square feet of rear yard area, that affects how you lay out an addition or ADU well before the first line is drawn.

When a Survey Is Non-Negotiable

If your title report references easements by deed book and page but doesn't include dimensioned locations, you can't accurately plot them on a site plan without a boundary survey. The same applies when an easement's recorded width is expressed as a centerline distance and the centerline location isn't documented relative to existing improvements.

A licensed land surveyor locates easements relative to actual property corners, flags any discrepancies between recorded documents and field conditions, and identifies undocumented encroachments that may complicate your permit. For projects where lot-line-adjacent work is planned — rear ADUs, side yard additions, any structure within 20 feet of a property boundary — a survey is often the most cost-effective risk mitigation available. The cost of a survey is a fraction of what a redesign costs once plan check has already flagged a structural encroachment into a recorded utility easement.

Frequently Asked Questions

Final Thoughts

Easements are one of those constraints that reward early attention and punish late discovery. If you're planning an ADU, addition, garage conversion, or any project where the footprint pushes toward property boundaries, pull your title report and share it with your drafter before design begins — not after you've already committed to a layout. The team at Sunny Drafting & Design works through easement conflicts regularly as part of site plan preparation, and catching them at the outset is always the more efficient path. Reach out to discuss your project and we'll help you map what's buildable before the first drawing is produced.