Patrick Isherwood on a missed opportunity in copyright law.

Patrick Isherwood is a partner at Frere Cholmeley Bischoff.

The recent settlement of the Cala Homes v McAlpine High Court action for £1.85m brought an end to a piece of litigation which has attracted an unusual level of interest in legal and business circles.

The original judgment by Mr Justice Laddie on liability in July 1995 held that Cala was the joint owner of the copyright in certain architectural drawings, prepared for it by external architects. Such was the contribution of Cala's in-house architect, that Cala was held to be the main author of the designs in question.

The Judge dismissed the argument from McAlpine that artistic copyright could only be enjoyed by those who wielded the pen.

He was also not persuaded that house designs which bore some resemblance to earlier designs, lacked sufficient originality to entitle them to copyright protection.

This prevented the hearing of McAlpine's appeal on liability and the airing before the judge of some key points of principle in relation to the account of profits exercise, an area in which there is a dearth of English legal authority.

In its account, McAlpine sought to derogate very substantially from its gross profits and also argued that in looking at the profit, which was properly attributable to house designs, a distinction should be made between that profit and the overall profit derived from building the houses themselves. This was dependent upon a number of factors which owed nothing to the design itself, including a notional value which could be attached to the land and its amenities.

Some guidance on these difficult points is found in decisions in patent cases where the copyright of a protected invention is infringed as part of a larger product, for example in a patented braking system then used in a car. Commonwealth courts have tended to adopt this approach.

Thus an interesting opportunity to develop a seldom explored area of the law of damages was missed.

The Cala case is still important, although it is submitted that it has developed law on authorship rather than departed in any way from established principle.

On a practical level, it highlights the risk of deliberate copying even in a field where imitation of winning features is a normal practice.