The tradition of carving faces into vegetables dates back to the Celts. As part of their autumnal celebration, the Celts carved faces into turnips and squash to light the way to their homes. They lit their pumpkin lamps to encourage the good spirits to visit them.

You might therefore think that candle light belongs to another age but you would be wrong! Rights to light and the amount of light a candle casts can be important.

It was for many years held to be a good working rule that where light to a room is interrupted by a neighbouring building so that the room is left with half its area, at the working plane, lit to a certain minimum standard, then that room, however much light it lost through neighbouring redevelopment or otherwise, was not actionably injured by the interruption of light to the window.

That minimum standard was one lumen, the equivalent light from a standard candle at 1ft distance which came to be known as the 50/50 rule.

This so called 50/50 rule was rejected in the 1967 decision in Ough v King in which the judge found that even where a room was left adequately lit for over more than 50% of its area, it was still deemed actionably injured. Unfortunately, no other standard of measurement of light was substituted in this case.

The 50/50 rule has nevertheless remained a good working guide in claims for interference with rights of light in commercial cases. In domestic cases it is likely that an obstruction amounting to less than 50% adequacy is an injury, as much as over 55% is not, with the problem cases being those in between!

The amount of light therefore to which an owner has a right is not necessarily all the light they currently enjoy. A right of light entitles an owner of property to receive sufficient natural light to allow a room to be used for its ordinary purpose. As a result, the amount of light required can depend on the type of property concerned and the type of room itself.

The important point to remember is that rights to light are private property rights. They are not part of planning law although obtaining planning permission is one of the factors that may be relevant in deciding what is the most appropriate remedy if say a developer infringes rights to light and whether the judge should grant an injunction or award damages.

The Law Commission published its Rights to Light report in December 2014, which included recommendations for a new statutory test on remedies for an infringement, a statutory notice procedure for issuing injunctive proceedings and simplification of the systems relating to rights to light. However, the introduction of these proposals is likely to be some way off.

Whilst technical analysis of what is the minimum standard of light may have moved on from considering the amount of light from a standard candle at a 1ft distance, the uncertainties involved are still enough to keep developers awake at night.