In most cases, landowners understand what encroachment and easement are. It is also important for adjoining landowners to understand lateral support and subjacent support, which are less familiar areas of law.

Lateral support is a legal theory involving adjoining landowners. From a legal standpoint, landowners have the right to receive natural and physical support from properties that border their land.

What Rights Do Landowners Have Concerning Lateral Support?

There is lateral support when adjoining lands are side-by-side. Naturally, the land should be protected against subsidence by its neighboring land(s) and be supported against slippage, cave-in, and landslides.

Subjacent support exists when the adjoining lands are above and below. In other words, it is the right of surface land to be supported against subsidence by the land underneath it.

A landowner has a common law right to lateral support. Landowners can expect that neighboring properties will support their land in its natural condition. In the event that an adjoining property is damaged as a result of excavation or substantial changes undertaken by a neighbor, the owner of the damaged property can sue.

It is necessary to take care and skill to preserve the adjoining land in its natural state, without regard to any buildings or structures. Excavating landowners are not required to support buildings or structures on adjoining lands. They are also not liable for damage caused to buildings or structures adjacent to their property as long as the adjoining land is supported, except as otherwise provided by law.

When Is Someone Liable for Disturbing Another’s Lateral Support?

There are two general categories of liability for damaging another landowner’s right of lateral support:

By law, a landowner is entitled to receive lateral support from adjoining lands. The right to support is subject to the adjacent landowners’ right to excavate for construction and improvement. You have the right to lateral support from your neighbors’ lands, but your neighbors do have the right to excavate their land. The landowner must notify adjoining landowners (and owners of buildings or other structures on adjoining lands) when and how deep the excavation will be.

Suppose property owner B excavates land from his property and, as a result, damages neighbor A’s lateral support. In that case, B will generally be held liable for any landslips, landslides, or flooding. During excavation, neighbors must take extra precautions to protect neighboring properties. Most states treat such disturbances as strict liability, meaning B does not have to be at fault for disturbing A’s lateral support – only that he does disturb it.

The excavating landowner must give the adjoining landowner a reasonable amount of time to take measures to protect their structures if the excavation will be deeper than the walls or foundations of adjoining buildings or structures. For this purpose, the excavating landowner must also allow the adjoining landowner access to their land. If the adjoining landowner wishes, they may waive the 30-day window.

When the excavation is deeper than 9′ feet at the point where the joint property line intersects the curb, and the adjoining landowner has buildings or structures whose foundations are at least 9′ feet deep, the excavating landowner, if permitted to enter on their neighbor’s land, is required to protect the neighbor’s land or buildings. The excavating landowner is liable for any damage other than minor settlement cracks.

Lateral support is a common law right. It is an absolute right inherent in the land. Although this right refers to the land in its natural state, it does not mean that an excavating landowner is immune from liability for damage just because his neighbor’s land contains a building and is “altered” from its natural state. If damage occurs, the excavating landowner must prove the weight of the neighbor’s building was the primary cause of the damage by applying downward pressure and contributing to the subsidence of the soil.

In cases where construction occurs on neighboring property, most courts distinguish between the condition of the land and determine liability accordingly. These are the most common distinctions:

  • Added Weight: If buildings improve land and an adjacent landowner’s excavation causes that improved land to collapse, the excavator will be liable only if they acted negligently in the construction. In the event that B did not exercise due care to avoid disturbing A’s lateral support when B built a house on neighboring land that cannot, B would be held liable for any damages that resulted.
  • Natural State: Strict liability does not attach to the excavator’s actions unless Plaintiff shows that, because of Defendant’s actions, P’s improved land would have collapsed even in its natural state. (In order for strict liability to apply, P must show that the improvements on their land [i.e., shrubs, fountains, structures], did not contribute to the collapse of the land.

Rights and Remedies

Both lateral and subjacent supports result from land subsidence, not excavation. In other words, a lawsuit may only be filed after the dirt has fallen. It does mean, however, that a landowner may bring a separate lawsuit for each occurrence, even if there was only one excavation.

A landowner whose property has been damaged by excavation can sue. In addition, a landowner whose property has been damaged by an excavation conducted by a previous owner has the right to sue. Non-owners may also file a claim. The lessor of a property damaged by excavation may sue to recover their rent as damages.

Both the excavating landowner and the contractor may be held jointly liable. It is unlawful for the landowner and the contractor to agree that the landowner is exempted from liability for the damage caused by the excavation. A bona fide successor-in-interest to the person who removed the lateral support is not liable for damage caused by excavation. In other words, if Owner A excavated the land and Owner B owns the property now, Owner B cannot be sued for the damage done. This is not necessarily true if the transfer was made to avoid liability.

Most landowners should try to prevent any damage from occurring in the first place. In order to obtain an injunction, a landowner must demonstrate that irreparable damage will be caused if the neighbor is allowed to continue excavating. The courts have the discretion to award monetary damages instead of barring the excavation. The monetary award is determined by calculating the diminution in value caused to the landowner by the excavation.


As the world becomes increasingly crowded with a greater housing density, problems involving injuring adjacent landowners become increasingly evident. It is better to confront this issue before the damage has been done, and this holds true for both the landowner engaged in construction and the adjacent parcel owners. Getting experts to advise and make recommendations on how to avoid damage is an excellent practical method of minimizing damage and the often-substantial remedial (and legal) costs that can otherwise be anticipated.

If you are suffering damage, you should obtain legal and expert advice as soon as possible to see whether injunctive relief may be available or, if not, whether damages may be claimed. Liability of subsequent landowners of the offending neighbor is not always guaranteed, so delaying seeking relief is not always advisable.

Should I Contact an Attorney?

Suppose the lateral support for your property has been disturbed, or you are facing liability to another person for disturbing their property’s lateral support. In that case, it is highly recommended that you contact a property attorney. An attorney can help you understand your case and can defend your rights.