The tragic death of three children in a house fire led to a council design team being sued for negligence. The case went to the Court of Appeal, and laid down some important rules on designer liability.
What does it take to be guilty of professional negligence? And who would have imagined that a choice of window design for a row of terraced houses would have led to this tragic story?

On the night of 14 October 1991, William Adams was unwell and decided to sleep downstairs. He woke to the smell of smoke. To his horror, he discovered the staircase was on fire. He shouted to his wife, who was sleeping upstairs with their three children. He tried to reach them but the smoke and flames drove him back. As he went outside for air, the door with its deadlock slammed shut behind him.

Mrs Adams, fully awake by now, tried desperately to save the children, but she couldn't open the bedroom windows. They were locked, and the key was downstairs hanging on a keyrack in the kitchen. She finally managed to smash through the toughened glass double-glazing, but fell to the ground through the jagged opening, severely lacerating herself. The three children, aged seven, four and three, died in the fire.

Two years before, Rhymney Valley District Council had replaced the windows in this run of old colliery houses in Tredegar. Number 103 Jubilee Road, where the family lived, was a mid-terrace two-storey dwelling.

The new windows were hardwood-framed and of standard design. A mullion divided the fixed pane from a single hinged unit that opened outwards. The windows were lockable at the handle with a removable key. With three nippers in the house, Mr Adams thought it would be best to keep the large windows locked and hang the key up downstairs.

If you are a designer of buildings – or, as in this case, a local authority refurbishing housing – you have a legal duty to design and build with due regard to the safety of occupiers and visitors.

When the council decided to install new windows as part of its refurbishment of 9000 homes, it was obliged to take such care as was reasonable to ensure that those living at 103 Jubilee Road were safe from personal injury.

The windows could have been installed with button-release handles instead of a removable key – a fact well known at the time. So, was the council design team negligent in its choice of lock and removable key?

That choice was made by a member of the housing department staff without consulting the fire service, the police or the British Standards.

There were many occasions in life when a reasonable man may adopt either of two courses without being thought negligent

All this came out in the first trial, at which Mr and Mrs Adams sued Rhymney Council for their loss and Mrs Adams' injuries.

In evidence, an expert fire officer and two other experts were critical of the decision to provide a window lock with removable key. But three other experts – an architect, an engineer and a surveyor – thought it was best to have a window of that size locked if small children were about.

The judge considered there was a conflict between the need to provide a means of escape and the need to prevent children falling out. He concluded that the choice of window was a decision any competent designer would have made at the time. The council was not negligent and no compensation arose.

Last month, the case came to the Court of Appeal in William Russell Adams & anr vs Rhymney Valley District Council, where three judges weighed up the council's design choice. Lord Justice Sedley was plain. Nobody had even considered at design stage whether a removable key created a risk that the window could not be opened in an emergency, nor had anyone balanced it against a button release.

He said the failure to take care arose from the failure to obtain proper advice – the designer deprived himself of the opportunity to make a choice between all the alternative courses available, so the negligence was in failing to consider all the options. He found for the Adams.

The two other judges disagreed. There were many occasions in life when a reasonable person may adopt either of two courses without being thought negligent. The right test was to ask not if there was a safer course that might have been adopted, but to ask if the chosen course – the choice of design – was one that a person skilled in that area would reasonably make, judging by the standards of the day.

The standard had to be reached irrespective of whether others had been consulted or not. It was, at that time, common for houses to have lockable windows with removable keys on the first floor. The choice was not in error.