Boards bearing these words are often seen fixed over the windows of a house. They are put there when the owner fears that the light which he has enjoyed for twenty years may be taken from him by some new buildings which are under course of construction. The legal position is as follows : The amount of light may be somewhat curtailed by the owner of the adjoining property erecting buildings thereon, provided that the letting or selling value of the house having the ancient lights is not thereby reduced, and the comfort and convenience of the occupier of it is not materially affected, even though a large portion of the light, which was previously enjoyed, has been lost.

If the building erected on the adjoining land causes an obstruction which will prevent a reasonable amount of light to the windows of the house, the owner of the latter may take proceedings to enforce the demolition of the new building, or he may claim damages.

The owner of the house having ancient lights may improve but not increase them, so that if the windows are enlarged, or increased, the owner of the adjoining property may obstruct them, until they have been reduced to their original form and number. The ancient 130 lights should not, however, be obstructed, unless that is unavoidable in curtailing the additional light.

Ancient lights may be abandoned by closing them, with the intention of abandoning them, or by erecting a new house in place of the other, but having a deviation on the frontage line, next to the property overlooked. The right to light will not, however, be lost by merely setting back the new house on a line parallel to that of the original house.

If no steps are taken to obstruct the access of light to new windows for a period of six years, the Court will be reluctant to intervene in favour of anyone who has neglected to assert his right to make such obstruction.

No right can be acquired by lapse of time to the enjoyment of the view from the windows of a house. Such view can, at any time in the absence of any arrangement to the contrary, be obstructed by the erection, on other property, of buildings, if the latter do not interfere with any acquired right of light to the house.

The owner of a house cannot acquire any right of access of air from the adjoining lands, but the building by-laws of urban districts provide for a certain amount of air space at the backs of houses to be erected or other space between them.