Encroachments, Party Walls and Shared Structures
Boundary problems are discovered at the worst possible time — during a survey for a sale, or when a neighbor starts building. What decides them is rarely the fence; it is the survey, the deed language and how long everyone has behaved as though the line was somewhere else.
What this report covers
- A survey, not a fence, establishes the boundary; fences frequently sit somewhere else entirely.
- Long undisturbed possession can ripen into title or an easement, on state-specific time periods.
- A recorded boundary line agreement or easement resolves most disputes at a fraction of litigation cost.
- Party wall rights and repair obligations come from a recorded agreement or, absent one, from state law.
- Title insurance may or may not cover an encroachment depending on the survey exception in the policy.
Boundary disputes almost never start as boundary disputes. They start as a sale that has hit a survey, a neighbor pouring a foundation, or a fence being replaced after thirty years — and at that point everyone discovers that the line they have all assumed is not the line in the deeds.
Establishing where the line actually is
Nothing is decidable until the boundary is fixed by evidence rather than by habit. The sources, in order of weight:
- The deed's legal description, which controls, and which references either a recorded plat, a metes and bounds description, or the public survey system.
- A current boundary survey by a licensed surveyor, who locates the description on the ground and sets markers.
- Recorded plats and prior surveys, which may disagree with each other and with the current one.
- Monuments on the ground, which in some states outrank measurements where the two conflict.
Fences, hedges, driveways and walls are evidence of what people have done, not of where the line is. They become legally significant only through the doctrines below.
Every route out of a boundary problem — agreement, removal, easement, litigation — needs a survey. Ordering one before the argument develops also frames the conversation as fact-finding rather than accusation, which is usually the difference between a signed agreement and a lawsuit.
Why waiting is not neutral
Two doctrines convert long-standing intrusions into rights:
| Adverse possession | Prescriptive easement | |
|---|---|---|
| Result | Ownership of the strip transfers | A right to keep using it |
| Typically requires | Possession that is open, notorious, continuous, exclusive and hostile | Use that is open, notorious, continuous and adverse |
| Exclusivity | Required | Not required |
| Common example | A fenced strip mowed and used for decades | A shared driveway crossing the line |
| Period | State-specific, commonly five to twenty years | State-specific, similar range |
Permission defeats both. Use that is permitted is not adverse, which is why a short written license — "you may keep the shed where it is until either of us gives notice" — is the cheapest protective step available to a landowner who does not want a fight but also does not want to lose land. Sending it, and keeping a copy, restarts nothing and prevents everything.
The four ways an encroachment ends
- Removal. The encroaching structure is taken down or moved. Cleanest, and hardest where the structure is a building rather than a fence.
- A boundary line agreement. Both owners agree where the line is and record it. This is the workhorse remedy: it costs a survey and a modest legal fee, and it binds successors.
- An easement. The line stays where it is and the encroaching owner receives a recorded right for the structure to remain, often for its life rather than in perpetuity.
- Purchase. The affected strip is conveyed, which usually requires a lot line adjustment approved by the local authority so neither parcel becomes non-conforming.
Where none of these is achievable, the proceeding is an action to quiet title, which fixes the boundary conclusively and binds future owners. It is slow and expensive, and its main value is finality.
Party walls and shared structures
A party wall stands on the line and serves two buildings. The rights are straightforward where a recorded agreement exists and improvised where one does not, in which case most states apply defaults: each owner may use the wall for support, neither may weaken it or remove support, and repair costs are shared in proportion to use or benefit.
The recurring problems are work-driven. One owner demolishes their building and exposes the shared wall to weather. One owner cuts pockets for new joists and weakens the other side. One owner waterproofs their face and traps moisture in the middle. In each case the party who caused the harm bears it, and in each case the argument is about causation, which is why photographs before work starts are worth more than any clause.
Roof overhangs, gutters discharging across a line, tree limbs and encroaching foundations follow the same analysis: a continuing intrusion supports a claim, permission defeats prescription, and a recorded agreement ends the argument.
When it surfaces at a sale
Most encroachments are found by a buyer's survey. The closing then depends on whether the title company will insure over the problem, which turns on the survey exception in the policy and on the nature of the intrusion — a fence is usually insurable, a garage corner over the line usually is not without an agreement in place.
Sellers who know of a boundary irregularity are generally better off resolving it before listing. The cost of a survey and a recorded agreement is small and predictable; the cost of discovering it three days before closing is a price reduction negotiated under time pressure, which is the same dynamic that makes unpermitted work so expensive at the point of sale. Where the structure at issue also required approvals — a wall, a fence above a height threshold, a shed near a boundary — the association's approval record is worth checking at the same time, because two defects on one structure are usually cured in a single negotiation.
Where the structure at issue was built rather than merely placed, a second question follows the first: whether it was permitted at all. A halted or unpermitted build and a boundary dispute are frequently discovered in the same week, and they are resolved by different offices on different timetables.
Sources
- Cornell Legal Information Institute — Adverse Possession
The doctrine by which long occupation can transfer title, and its elements.
- Cornell Legal Information Institute — Easement
Express, implied and prescriptive easements, and how each is created.
- Cornell Legal Information Institute — Trespass to Land
The claim a continuing physical intrusion gives rise to.
- Cornell Legal Information Institute — Quiet Title Action
The proceeding used to settle a disputed boundary conclusively.
- Bureau of Land Management — Cadastral Survey
The survey framework that underlies legal descriptions across much of the country.
- Consumer Financial Protection Bureau — Title Insurance
What an owner's policy covers, and where survey exceptions sit.
Questions readers ask
My neighbor's shed is a foot over the line. Can I make them move it?
Often yes, if you act. The remedy for a continuing trespass is an injunction requiring removal, plus damages. Courts weigh the cost of removal against the harm, and small innocent encroachments sometimes end in damages instead of removal. What changes the answer is time: leave it long enough and the neighbor may acquire rights, so the practical advice is to raise it in writing early even if you have no wish to escalate.
Who pays to repair a shared wall?
If there is a recorded party wall agreement, whatever it says. If there is not, most states apply a default: each owner may use the wall, neither may weaken it, and repair costs are shared in proportion to use or benefit. Where one owner's work damages the other's side, that owner bears it. The absence of a written agreement is the usual reason these disputes become expensive.
Does title insurance cover an encroachment?
It depends on the policy and, specifically, on the survey exception. Standard policies commonly exclude matters an accurate survey would reveal, which is exactly what an encroachment is. Where an owner buys extended coverage and provides a current survey, the exception is often removed and encroachments can be covered. Check the exceptions schedule of your policy before assuming either way.
