Easement

An easement is a legal right for one party to use a portion of another's property for a specific, limited purpose — without owning that land. Common examples include utility easements (so a power, water, or sewer provider can run and maintain lines), access easements (a shared driveway or a right-of-way to reach a back lot), and drainage easements. Easements are typically recorded against the property's title and run with the land, meaning they bind future owners, not just the current one.

Easements matter for construction because they restrict where you can build. You generally cannot place a structure — including a detached ADU or accessory structure — on top of a utility or access easement, since the holder must keep it clear for their use. On a tight lot, an easement running through the backyard can shrink the buildable area as effectively as a setback does, and it is a detail that is easy to overlook until a survey or title report surfaces it.

This is why checking title and a current survey early is part of feasibility, especially for an urban lot split, where new lot lines, access, and utility easements all have to work together. An easement can also affect financing and what a buyer or lender will accept. Easements are distinct from setbacks (a zoning rule) and from public rights-of-way, though all three shape where a building can sit.

The types of easements on a property, their exact locations and terms, and how they affect a build are specific to each parcel and are legal matters. This is a general overview, not legal advice — review your title report and survey, and consult a qualified professional, before assuming a given area is buildable.