Disturbance and Remedies, generally speaking-, when an easement exists, whether that easement has come into existence by express or implied grant or covenant, or by prescription under the Act, whoever has a right to enjoy that easement is entitled to sue for damages or injunction, or both, for disturbance or interruption of the enjoyment, or for an injunction to prevent a threatened disturbance.

In former days the ordinary remedy for an actual disturbance of an easement right was by action at law upon the case, and damages were the common remedy, with a subsequent appeal to Courts of Equity " to grant an injunction in aid of the legal right where there was danger of irreparable mischief, or where an injunction was required to prevent multiplicity of actions." Since the passing of the Judicature Act the High Court has had all the jurisdiction of the Court of Chancery and of the Courts of Law, and it has become the practice to seek equitable remedies for these cases almost as a matter of course, but it is important to bear in mind that for the most part the matters in dispute are matters of fact, suitable for a jury to decide, including an estimate of the amount of damages which would suffice to compensate the plaintiff for the injury done to his legal right. If a good cause of action is established, plaintiff is entitled to remedy in the shape of some damages as a matter of course, which may be either nominal or substantial ; but whether he can also obtain relief by injunction depends on the judicial discretion of the Court with reference to the facts of the case. When a disturbance of enjoyment is threatened in the matter of ancient lights, an injunction to restrain the defendant from carrying his threat into execution is ordinarily the appropriate remedy, and would be granted where really substantial injury was threatened ; but when no action has been taken by the owner or occupier of a building with ancient lights until the owner or occupier of a servient tenement has completed his building, it must not be assumed that a mandatory injunction to pull down the offending building will be granted as a matter of course. Judges, in the exercise of their judicial equitable discretion, will take account of the injury which would result to a defendant from compelling him to demolish substantial portions of any building which he may have erected in good faith, as well as of the injury which would be inflicted upon plaintiff from letting the building stand. If the plaintiff's conduct has been such as to imply acquiescence in the erection of his neighbour's building, he must not expect to be able to obtain a mandatory injunction to pull the building down.

If a defendant had run up blank walls or screens for the express purpose of blocking plaintiff's windows, for which an easement right had been acquired by any means, then no doubt, on proof of the facts, defendant would ordinarily be compelled to remove the obstructions ; but between the two extremes of a person erecting structures intended only to obstruct a neighbour's lights while not otherwise benefiting himself or his property, and the case of a man building with all good faith on his own land for the improvement of his own property without design to injure his neighbour's, there may be many shades of difference in the facts, which need to be taken into account; and judges, dealing with the facts of each particular case, will grant or refuse requests for mandatory injunctions in whole or in part, or on terms, as may appear to be most reasonable and just under the proved circumstances of each case.

It may be noted that, if the enjoyment of light is interrupted, the interruption may cause injury, not only to a tenant in possession, but also to the landlord or to a reversioner, by diminishing the value of his reversionary estate, and in all such cases an action will lie at the instance of any of the persons injured.

Also it may be noted that if an action is brought with a claim for damages only, any damages which may be awarded will relate to injury inflicted before action, that is - to past injury ; and if the interruption is continued it is open to the same plaintiff to institute a fresh action for further damages for injury inflicted since the former suit was instituted, and, in theory at least, fresh actions may be started again and again for damages for the same obstruction, but for different periods of time until such time as the defendant may of his own motion abate the nuisance. When, however, the plaintiff has sued for an injunction, and damages have been awarded in lieu of injunction, the damages thus awarded put an end to litigation as regards the particular interruption or obstruction complained of. The damages cover not only the past but the future, and, an injunction having been refused, the defendant can maintain the existing obstruction ; but if he afterwards adds to the obstruction anything not contemplated or in existence at the time of action, the added obstruction may give a fresh cause of action if it causes further injury to the ancient lights of the plaintiff.

When disputes have arisen concerning obstruction to light, various excuses have been put forward at different times with the object of trying to avoid liability for obstruction, but generally without effect. The real question always is, whether the particular structure complained of does, as a matter of fact, substantially injure the plaintiff by diminishing his light to an actionable extent, as previously explained. Sometimes a dominant owner decides to improve his windows so that they may admit more light than before. This he is entitled to do without thereby giving any right to a servient owner or occupier to obstruct; but if he enlarges his windows, or if he opens fresh ones, the servient owner may obstruct the new windows or the enlarged parts of the old ones if he can do so without obscuring those which are old, or the old parts of the enlarged windows.

Formerly it used to be thought that, if a dominant owner enlarged his privileged windows, or opened new ones in their neighbourhood which could not be obstructed without obstruction to the ancient lights also, the servient owner then had a right to obstruct all the windows so enlarged or opened.

The opinion was that, inasmuch as no new or enhanced burden could be created by a dominant owner without the consent of the servient owner, the servient owner could certainly build so as to block what was new, and it would be the fault of the dominant owner in such cases if the enjoyment of his ancient lights was also interrupted and in time lost altogether.

Later, in the case of Tapling v. Jones, finally decided on appeal in the House of Lords, it was held that an easement of light acquired under the Prescription Act was absolute and indefeasible, and could not be destroyed or interrupted because the owner had enlarged his old windows and opened new ones which were not privileged.

Lord Chancellor Westbury pointed out that the Act of opening new windows was not a wrongful one, but in law an innocent act, and no innocent act can destroy the existing right of one party or give an enlarged right to the other.

Similarly the right of an adjoining servient owner to build on his own land is neither enlarged nor restricted as a consequence of the opening of any new windows by a neighbour, so that the servient owner may exercise his right to build as he likes, except that he must not build in such a way as to obstruct ancient lights.

Evidently, if a dominant owner can safely go on enlarging his ancient windows and opening new ones, under cover, as it were, of those which are old, he might by degrees better the position of his dominant tenement, and in time impose serious additional burdens on the servient tenement, - if he could in the end maintain as full rights or privileges for the enlarged and new windows as for the old ones.

Courts administering law and equity would not favourably regard such a course of conduct, and if a servient owner were to build so as to obstruct the whole of the light old and new, as the only available means for stopping the accrual of new burdens, it is probable that the dominant owner could not under such circumstances obtain mandatory injunction, but only damages with reference to the ancient lights which might then be lost.

It may be observed that the decision of the House of Lords in Tapling v. Jones overruled several prior decisions of the Courts below, and it is not altogether in apparent accord with the later decision of the House of Lords in Colls v. The Home & Colonial Stores.

In some future cases it may be argued that the opening of new or enlarged windows overlooking a servient tenement, in directions where windows previously existed, does not necessarily amount to the imposition, or even attempt at imposition, of new or increased burdens upon that tenement ; and it may perhaps be further argued that, in accordance with the principles laid down in Colls v. The Home & Colonial Stores, the enlargement or multiplication of window space by the dominant owner rather tends to diminish the burden on the servient tenement, because with superabundant lighting through many or large windows in the dominant tenement, it may be possible for the servient owner to build more extensively without reducing the superabundance of light below a point where there will still be enough left for all ordinary purposes of habitation or business.

The true measure of the burden imposed on the servient tenement is the amount of restriction to which he must submit when he wants to erect buildings, etc., on his own land, and he has no grievance unless that restriction is increased, nor has the dominant owner any real grievance unless his lights are obstructed as to leave him in a worse position as regards the lighting of his premises than he was in before opening or enlarging his windows.