If you have a building with windows and therefore rooms into which light flows, then in general terms if you have a right to light. For instance, if someone interferes with light from which you have benefited for 20 years, usually by seeking to construct a building next door or possibly extending upwards or outwards, then you may have either a claim for damages or a claim for an injunction to stop the building being built.
For about 100 years, the Court has used research conducted by Percy Waldram to decide whether the light remaining in a room following such an action is sufficient to prevent an interference with the enjoyment of that room by the property owner.
Back in the 1920’s, Percy concluded that a 1-foot candle (approximately 10 lux) of light was just about sufficient to be able to undertake reading or clerical tasks. Applying that calculation, an expert reporting to the Court can consider whether 50% or more of the total area of a room can see 0.2% of the sky dome (which on a dull day is assumed to be 5000 lux), at the working plain (0.85 metres or table height). If so, the room would be adequately well lit for ordinary purposes. Should a reduction in light occur as a result of development thereby reducing it below this standard, then it can be interpreted as a material loss of light.
Although that test was recently criticised, the Judge did not accept that he should ignore the Waldram test. However, he did accept that in some cases the results of the test would only provide a starting point and the Court was receptive to considering other methods of measuring light loss.
The Prudential is seeking to develop a building on the corner of Wells Street and Oxford Street in London. The adjoining owner has sought an injunction to prevent the Prudential interfering with its rights of light. In its defence, the Prudential has argued that the Waldram analysis does not provide a reliable view of the effect of the diminution of light on the amenity of rooms in the building. They say, amongst other things, that the Waldram test ignores the contribution of reflected light, it is based on an unrealistic model of the sky dome, it fails to take into account the effect of sunlight or seasonable variations in the amount of light enjoyed by buildings and it wrongly assumes that one lumen per square foot provides adequate light.
Times have changed somewhat since the 1920’s. For a start, the amount of light required to undertake tasks is probably now regarded as much greater. In an article published in 2009, it was suggested that the standard should be more like 25 lux. The recommendations for light in an office space is somewhere between 300 to 500 lux. Clearly, electric lighting is required to meet modern day office standards.
Our knowledge of the amount of light to be received from the sky dome, is a lot more sophisticated than it was in the 1920’s and therefore the potential for updating the methodology is also that much greater. We also have much better records of the variations in light at various points of the country.
With climate records enabling much better modelling and software being so advanced, complex calculations could be undertaken more easily.
It will be interesting to see whether the Court is prepared to abandon the Waldram method and to adopt a new test. If so, if it will prescribe it in such a way as to provide certainty.
Will the Court take the view that 10 lux is now inadequate to provide sufficient light to undertake tasks according to the ordinary notions of mankind? It is not being suggested that one needs 300 to 500 lux for those tasks, but rather the level of natural light required to give a room a feel of being lit naturally.
Furthermore, is there a difference between the amount of natural light required in an office as against a home, factory, school or wherever?
Does the amount of natural light affect rental income? Certainly, rents charged for office basements are much less then for offices above ground. But assuming there are windows and natural light, at what point does the interference with that natural light affect the rent that can be charged?
It is to be hoped that the case of Sirosa Properties v Prudential Insurance Company Limited will require determination by the Courts so that we can see whether the Courts are amenable to a challenge to the Waldram test and prepared to give guidance as to updated calculations.
