Damages for trespass are compensatory. In certain circumstances a landowner can recover compensation notwithstanding that he might have suffered no loss in the conventional sense. In such cases, damages are measured by the benefit the trespasser receives by the use of the land.
A recent case on this subject concerned an advertising hoarding and platform which were affixed to the defendant's wall intruding into the airspace over land owned by the claimant. The judgment states that the calculation of damages for trespass is flexible but the common approach is the "hypothetical licence fee". This means that damages will be assessed on the amount that the parties would have negotiated as a reasonable licence fee.
Stadium Capital Holdings (No.2) Ltd v St Marylebone Property Company Plc and another (2010).