Under the general common law of nuisance, no one can complain of a sudden or unannounced obstruction of a long-standing source of light unless the light is said to be ancient, as in ancient lights.
Jowitt’s sets out the law as follows:
“Windows, glazed or unglazed, through which the access of light has been enjoyed otherwise by consent or permission for twenty (20) years and upwards.
“The owner of an ancient light may increase the size of windows through which he has enjoyed the light or open new windows. But he will acquire no right to light for so much of an existing window as in an enlargement, or for a new window, until a new period of 20 years has run; and at any time within such period the owner of adjoining land may erect a screen which prevents the access of light to the enlargement or new window and may so prevent a further right being added to the existing right.”
Otherwise stated, as described in the 2007 edition of the Canadian Encyclopedic Digest:
“A complainant must have the right to ancient lights before that person can object to an obstruction (of light), and the obstruction must be substantial.”
The law as it relates to nuisance generally, and to ancient lights specifically, is subject to statute law which, in any given jurisdiction, may alter the common law.
In Back v Stacey, quoted in Colls v Home & Colonial, the Court wrote:
"... there must be a substantial privation of light, sufficient to render the occupation of the house uncomfortable.... It might be difficult to draw the line but the jury must distinguish between a partial inconvenience and a real injury to the plaintiff in the enjoyment of the premises."
In Parker v Smith:
The question ... is whether the effect of the defendant's building is to diminish the light ... so sensibly to affect the occupation of the plaintiff's premises and make them less fit for occupation."
To some common law sources, ancient lights is a species of easement. In Kelk v Pearson, Justice James wrote of ancient lights as an easement:
"... a right to prevent your neighbour from building on his land so as to obstruct the access of sufficient light and air to such an extent as to render the house substantially less comfortable and conveinent."
REFERENCES
- Back v Stacey (1826) 2 C&P 465
- Burke, J., Jowitt’s Dictionary of English Law, 2nd Ed., Vol. 1 (London: Sweet & Maxwell, 1977), page 101
- Colls v Home & Colonial Stores 1904 AC 179
- Kelk v Pearson LR 6 Chancery 809
- Parker v Smith 5 C&P 438
- The Canadian Encyclopedic Digest, 4th Edition (Toronto: Carswell, 2007), page 98.