ANCIENT-LIGHTS DOCTRINE
ancient-lights doctrine.The common-law principle by which a landowner acquired, after 20
years of uninter-rupted use, an easement preventing a neighbor from building an obstruction that
blocks light from passing through the landowner’s window. • The window (or other opening) is
termed an ancient light. This doctrine has rarely been applied in the United States. — Also termed
ancient-windows doctrine. [Cases: Easements 11. C.J.S. Easements § 51.]
“[A] notice ‘Ancient Lights,’ which is often seen affixed to the wall of a building, only
denotes a claim by or on behalf of the owner that he has acquired, by prescription or otherwise, a
right to a reasonable amount of light, free from interruption, over adjoining land; but it must not
be supposed that such a notice is necessary in order to protect a legal right.” 2 Stephen’s
Commentaries on the Laws of England 347 (Crispin Warmington ed., 21st ed. 1950).
“Under the English doctrine of ancient lights, which has been soundly repudiated in this
country, if a landowner had received sunlight across adjoining property for a specified period of
time, the landowner was entitled to continue to receive unobstructed access to sunlight across the
adjoining property; the landowner acquired a negative prescriptive easement and could prevent the
adjoining landowner from obstructing access to light.” 1 Am. Jur. 2d Adjoining Landowners § 90,
at 889 (1994). [Blacks Law 8th]