by Mark Pawlowski
Although English law has not accepted the existence of a natural right to a free flow of light, it does recognise a right to light through defined apertures which may be acquired by prescription at common law or by lost modern grant as well as under the Prescription Act 1832. But, apart from the question whether such a right has arisen by one of these recognised modes, there is also the question of what quantity of light the dominant owner is entitled to and how that quantity is to be measured. This article attempts to give some guidance on these two questions by reference to decided case law and recognised scientific methods of measuring the adequacy of lighting through a particular aperture.
How much light is the dominant owner entitled to?
It has been settled law since the House of Lords’ decision in Colls v Home & Colonial Stores Ltd [4] AC 179 that a landowner has no right to object to activities on neighbouring land merely because they reduce the amount of light passing through his windows unless the obstruction complained of constitutes a nuisance. Accordingly, the right to light gives rise to no more than a negative easement amounting to a right to prevent a neighbour from using adjoining land so as to constitute a nuisance to the dominant owner upon his own land: see Kine v Jolly [1905] 1 Ch 480. Whether or not a nuisance is committed will, in turn, depend on whether the effect of the neighbour’s building or development will be to diminish the light to the plaintiff’s land so as sensibly to affect the occupation of the plaintiff’s premises and make them less fit for occupation. In the classic words of Lord Lindley in the Colls case (at pp 208 and 209):
…generally speaking an owner of ancient light is entitled to sufficient light according to the ordinary notions of mankind for the comfortable use and enjoyment of his house as a dwelling-house, if it is a dwelling-house, or for the beneficial use and occupation of the house if it is a warehouse, a shop, or other place of business. The expressions “the ordinary notions of mankind”, “comfortable use and enjoyment” and “beneficial use and occupation” introduce elements of uncertainty, but similar uncertainty has always existed and exists still in all cases of nuisance, and in this country an obstruction of light has commonly been regarded as a nuisance, although the right to light has been regarded as a peculiar kind of easement.
Accordingly, any substantial interference with the dominant owner’s comfortable use and enjoyment of his house for the ordinary purposes of inhabitancy or business of the tenement according to the ordinary notions of mankind is actionable as a nuisance at common law. In the words of Lord Lindley in the Colls case (at p 210): “the question to be decided is not how much light is left, but whether the plaintiff has been deprived of so much as to constitute an actionable nuisance”.
In determining the amount of light which is required in the plaintiff’s house if it is to be conveniently usable according to the ordinary notions of mankind, the courts have adopted the view that scientific formulae provide no more than a helpful starting point for the judge in deciding any dispute as to the adequacy of light through a particular window. For example, Meredith J in Smyth and Smyth v Dublin Theatre Co Ltd [6] IR 692 said:
The evidence of experts is not as safe a guide as the evidence of those accustomed to use the room in question. The wearer of the shoe is the one best qualified to say if and where it pinches.
In Ough v King [7] 3 All ER 859, Lord Denning MR said (at p 861):
I think it is very helpful for the judge in light cases to have a view, as well as hearing the evidence of the experts…I would not myself denigrate the value of expert evidence. All I say is that a view can be a most helpful addition.
In Sheffield Masonic Hall Co v Sheffield Corporation [2] 2 Ch 24, Maughan J, while conceding the value of expert evidence, said:
I think it is safer to rely upon the view expressed in Colls v Home & Colonial Stores, and to consider whether, as a matter of common sense, there is such a deprivation of light as to render the occupation of the house uncomfortable in accordance with the ordinary ideas of mankind.
However, notwithstanding these judicial pronouncements, two scientific tests have been devised over the years to measure the minimum amount of light to which a dominant owner may legally lay claim to his tenement. These are “the 45 degrees” rule and the “50/50” rule to which I now turn.
The 45 degrees rule
Before the decision in Colls, there was considerable judicial authority establishing a specific test, derived from the provisions contained in the Metropolis Management Amendment Act 1862, namely, that “if a street be narrow and if a wall be erected to such a height, as that a line drawn from the top of it to the base of an ancient window forms an angle of forty-five degrees with a horizontal line drawn also from the base of the window, then the wall will not be allowed to be carried higher” (Williams’ Rights of Common and other Prescriptive Rights (1880) p 357). As a rule of law, however, this test was emphatically rejected by the House of Lords in the Colls case, in which Lord Lindley said (at p 210):
There is no rule of law that if a person has 45 degrees of unobstructed light through a particular window left to him he cannot maintain an action for a nuisance caused by diminishing the light which formerly came through that window. But experience shows that it is, generally speaking, a fair working rule to consider that no substantial injury is done to him where an angle of 45 degrees is left to him, especially if there is good light from other directions as well.
In Charles Semon & Co v Bradford Corporation [2] 2 Ch 737, the defendants proposed to erect a building 73 ft high with a street 45 ft wide separating it from the plaintiffs’ building. It was held that, while the plaintiffs would be left with much less than 45 degrees of light, nevertheless, since the ground-floor windows of the plaintiffs’ building would still be unusually well lighted, the plaintiffs had suffered no actionable diminution. It is evident, therefore, that the rule has no hard and fast application. Moreover, the 45 degrees rule has now been largely discarded in favour of the more scientific approach conceived by Percy J Waldram in the 1920s, popularly known as the “50/50” rule. (For further discussion of the 45 degrees rule, the reader is referred to the judgment of Crossman J in Fishenden v Higgs & Hill Ltd (1935) 153 LJ 131-133 and Lord Selborne in City of London Brewery Co v Tennant (1873) 9 Ch App 220. For a detailed study of the subject, see also J Swarbrick, Easements of Light (1938).)
The 50/50 rule
Under this test, a room may be regarded as adequately lit for all ordinary purposes if 50% or more of its area receives not less than one lumen of light at table level (ie at a point 2 ft 9 in above the floor level). A “lumen” for this purpose is the amount of light received from one five-hundredth (0.2%) part of the sky on a dull, overcast day. The line joining the points in a room receiving this minimum quantity of light was formerly called the “grumble line” but today is technically referred to as the 0.2% sky visibility contour line (representing the accepted minimum amount of daylight adequate for work involving visual discrimination).
The 0.2% line is plotted on a daylight contour plan (“Waldram graph”) which shows the distribution of daylight within the room in question on the basis of present conditions and those that would be brought about if the neighbouring owner’s proposed development took place. This is achieved by first plotting the 0.2% sky visibility contour line (representing the accepted minimum amount of daylight adequate for all ordinary purposes), assuming existing conditions and then marking the 0.2% contour again, but this time on the basis that the proposed development already exists. In this way, a direct comparison can be made between the areas which are currently lit to 0.2% and those areas which would be lit to that level assuming the development had taken place.
The resulting contour will, in fact, split the room into a number of zones. First, there will be the zone of insufficient sky visibility where the sky visibility is less than 0.2%. Next, there will be a zone of adequate sky visibility both before and after the proposed new obstruction — a zone which is common to both sets of conditions. Third, there will be a zone which currently enjoys adequate sky visibility but which will no longer enjoy it with the proposed obstruction — the zone of loss of adequate sky visibility.
Having determined the relative position of the three zones and thereby measured the effect of the proposed development on the amount of daylight enjoyed by the room in question, it then becomes necessary to consider whether the same constitutes an actionable injury at law. In this connection, the adequacy of the remaining light (ie the adequate sky visibility area) is measured by reference to the “50/50” rule referred to above. Accordingly, the room will be regarded as adequately lit for all ordinary purposes if the adequate sky visibility area of the room accounts for 50% or more of the total area of the room.
The foregoing analysis assumes, of course, that the surveyor is able to see the present conditions of the room but is asked to estimate the effect of a proposed development. Frequently, however, he will be engaged after the development has taken place and will, therefore, need to estimate the conditions existing prior to the obstruction.
While, no doubt, the 50/50 rule provides a very accurate and scientific measurement of light by means of daylight contour plans, nevertheless, it has been judicially held to be no more than a convenient rule of thumb and should not be treated as a decisive test in all cases. Moreover, despite the rule, it is admissible to have regard to the higher standards expected for comfort in modern times. In the words of Denning LJ in Ough v King [7] 1 WLR 1547 (at p 1552):
…I think the judge was entitled to have regard to the higher standards expected for comfort as the years go by. As Upjohn J said in Cory v City of London Real Property (1954)…:
“The truth may well be that the standards of light required by normal inhabitants are increasing, and it is hardly to be doubted that they will increase, because modern offices are built on the whole with more light than old offices.”
I think that is right. In these days I would not myself be prepared to regard the 50/50 rule of Mr Waldram as a universal rule. In some cases a higher standard may be reasonably required.
In my judgment the judge directed himself quite properly. He then made this finding: “Previously it was just a light room: by the loss it has suffered, it has become a slightly less than light room. It now receives less light than is sufficient according to the ordinary notions of mankind”. That is a finding of fact a judge who has properly directed himself and has seen the premises. I see no reason whatever to interfere with it.
Diplock LJ put the matter in this way (at pp 1553 to 1554):
This appeal has really been presented on the basis that as a result of the labours of Mr. Waldram in the 1920’s there is now a rule of law that no one is or ever will be entitled to more light than amounts to not less than one lumen over 50 per cent of a room at table level. In the present case the amount of light of one lumen at table level extended, if I have worked it out accurately, to 51.27 per cent of the area of the room. It is therefore said that as a matter of law that cannot amount to a nuisance. The 50/50 rule is what no doubt was, in the 1920’s and perhaps later, considered to be a convenient rule of thumb. The real question is that which has been stated by my Lords and was asked by the judge of himself. The answer which he gave is one with which this court in my view cannot interfere.
In the light of the foregoing observations, assuming that the adequate sky visibility area of a room does not significantly extend above the 50% limit, it may well be possible to argue that an actionable injury still exists by application of the broad test of the common law invoking the ordinary notions of mankind.
Assuming that an injury to light is found to exist, the next stage will entail the valuation of this injury in terms of money. This is done by measuring the area over which the 0.2% contour has moved in the given room and then multiplying that area by an appropriate rate per sq ft (having regard to the range of rents in the locality and applying a certain percentage reduction in the rental value depending on the severity of injury sustained) and, finally, capitalising the result by a sum representing the appropriate years’ purchase. It is possible to make various refinements to the foregoing calculations. For example, in Mr John Anstey’s excellent handbook on the subject, The Valuation of Rights of Light (published by the College of Estate Management) a refinement is suggested in circumstances where a room does not suffer injury by a strict application of the 50/50 rule. At p 11 Mr Anstey states:
… for areas of loss which would not have been actionable injuries in themselves, lying between the 50/50 line and 75% of the whole room, the value should be halved, and for that part of the loss which occurs in the first 25% of the room, i.e. usually close to the back wall, a quarter of the standard rate ….
Where the premises in question are subject to both a freehold and leasehold interest, it may also be necessary to apportion compensation according to these respective interests. One approach is to calculate the lessee’s share of compensation down to the period of his next rent review under the lease, on the assumption that when the rent next falls to be reviewed, it will take into account the injury to light. On this basis, it is necessary to calculate the proportion of compensation payable to the lessee for the period to the next review date, taking into account an element of discount for the fact that the whole amount will be paid to the lessee in the first year. Accordingly, some adjustment will be required for the other years leading up to the review date, bearing in mind the figure for the appropriate number of years’ purchase. (For an authoritative guide to the 50/50 rule the reader is referred to B Anstey and M Chavasse, The Right to Light (1963)(*).)
Apart from assessing the loss of light to a particular room, it will be necessary also to take into account the loss of amenity generally that the proposed obstruction would occasion. In this connection, it is appropriate to refer to the judgment of Millett J in the recent case of Carr-Saunders v Dick McNeill Associates [6] 2 All ER 888; [1986] 2 EGLR 181, where he said (at p 896):
But I have to award general damages, and in my judgment, on the authorities which have been cited to me, I am entitled to take into account not only the loss of light but the loss of amenity generally, due to such factors as loss of sky visibility, the impression that the building at the rear is now closer than it was (though that is an optical illusion), the loss of sunlight and other such matters — in short, the general deteriorating quality of the environment. Also I have to bear in mind the fact that in any negotiations between the plaintiff and the defendants the plaintiff would certainly not be satisfied with the £3,000 which Mr Anstey considers appropriate. He would have a bargaining position because, unless he were bought out, the defendants would be inhibited in their development. In Wrotham Park Estate Co Ltd v Parkside Homes Ltd [4] 1 WLR 798; [1974] 2 All ER 321 this approach was applied to the award of damages for breach of restrictive covenants; and in Bracewell v Appleby [1975] Ch 408; [1975] 1 All ER 993 it was applied to damages for obstruction to a right of way (my emphasis).
A little later in his judgment, he said:
Accordingly, I am entitled to take account of the servient owner’s bargaining position and the amount of profit which the defendants would look to in the development of their site. I have no evidence of the amount of profit which the defendants are expected to make from their development — largely, I think, because the plaintiff was seeking a mandatory injunction and no one recognised that documents which would throw light on the profit to be made from the development were material and ought to be disclosed on discovery. But I have evidence of the general loss of amenity, given to me by the lay witnesses and corroborated to some extent by the expert witnesses; and it seems to me obvious that any dominant owner, negotiating with a servient owner for monetary compensation for the loss of light, would take into account the general loss of amenity which his premises would suffer.
In that case, Millett J, in addition to accepting Mr Anstey’s figure of £3,000 for loss of light, was prepared to award a further £5,000 for loss of amenity, bringing the total award to £8,000.
Clearly, the effect the proposed development will have on sunlight to the room in question will be a material consideration in most cases, and, in this connection, drawings depicting the likely shading created by the existing and proposed buildings will provide a helpful aid to determining the extent of injury under this head. Moreover, loss of warmth, loss of views, the extra cost of having the electric lights on earlier and for a longer period (this latter point was considered in Ough v King, supra, where there was evidence that the extra cost of lighting would involve a capital sum of £60) and the extra cost of space heating, in particular during the winter months, would all fall to be considered in any given case.
Millett J in the Carr case emphasised the need to consider also the plaintiff’s bargaining position in any negotiations between the parties and, in particular, the fact that the plaintiff would be unlikely to be satisfied with just a minimum figure calculated strictly in accordance with mathematical tests. Accordingly, the amount of profit which the defendant would look to in the development of his land is also considered a relevant factor in assessing damages, which, it is important to remember, are awarded in lieu of an injunction in this context and not merely in compensation for the loss of the actual legal right.
(*) Published by The Estates Gazette Ltd, but now out of print.