If you see something going wrong on a building site, do you have a legal duty to tell someone? This is a simple question with no simple answer, says Rupert Choat. But here’s the latest thinking …

Do you have common sense? Those working on construction projects obviously require it in bucketfuls but it is an elusive concept. One person’s common sense act can be another’s moment of madness. The gap between the two is the common sense trap. The gap is also found between how something is seen during a job and how it is seen when put under the courtroom microscope.

The latest instalment in the Hart vs Fidler saga (which Tim Elliott wrote on in Building, 15 June, page 65) shows how consultants and contractors alike can be caught in the common sense trap.

You may recall that the judgment concerned the collapse of part of a house during its redevelopment. The cause was inadequate propping by the contractor. As with so many cases where the law’s edges are tested, the party that seemed most at fault (here, the contractor) was insolvent.

The court held that the engineer was liable to compensate the developer that engaged him to design and inspect the permanent works. I say permanent works because the engineer was not engaged to inspect the contractor’s temporary works (that is, his work methods, such as the propping). The court said that the poor propping was obvious and dangerous and the engineer should have taken such steps open to him to obviate the danger, such as warning the contractor.

Over the past 30 years or so the courts have developed a “duty to warn” on the part of contractors where the design they are asked to build to is defective. Hart vs Fidler is a rare example in the analogous, but not identical, situation of a consultant owing a duty to warn where the contractor’s methods are defective.

The result might seem harsh to some. The engineer was inspecting to ensure the quality of the end product. Need he have concerned himself with how that end product was achieved? Common sense to me says yes, if there is an immediate danger to person or property and the inspecting consultant actually sees that danger.

But should the consultant warn the contractor if he sees dangerous horseplay by one of the contractor’s men on site – or on YouTube? How far does the duty to warn go?

Would a consultant with no inspection duty be held to owe a duty to warn in respect of a danger they should have seen on their way to a site meeting?

Does it apply where the inspecting consultant should have seen, but did not actually see, the obvious problem? Usually the answer will blur into addressing the question: did the inspector see anything? If the problem was obvious (and dangerous) any court is likely to decide, on the balance of probabilities, that the inspector actually saw it.

A further tester: what if there is no immediate danger to person or property but only the threat of adverse financial consequences – such as poor work? This is a classic distinction the law draws in deciding on the scope of a duty of care. Here the reasoning behind the Hart vs Fidler judgment is relevant. The court relied upon the solicitor’s duty to warn of obvious dangers even if they are not employed in relation to those dangers. These dangers usually do not threaten person or property but only the pocket.

It therefore seems a short step or two for a court to decide that an inspecting consultant owes a duty to warn in respect of obvious dangers that they see or should have seen even if those dangers were not within their scope and only threatened adverse financial consequences. After all, it is common sense!

Of course, much turns on the given situation and any relevant appointment terms. It would be an unusual case where a consultant with no inspection duty was held to owe a duty to warn in respect of a danger they should have seen on their way to a site meeting. Unfortunately the standard forms tend to be silent on this difficult topic. The duty to warn is therefore invariably an unwritten duty for which there is no additional entitlement to be paid.

It is no excuse that someone else is better placed to warn of the danger. It is perfectly possible for a duty to warn to be owed by more than one consultant or contractor on the same site in respect of the same danger. This makes sense – at least where there are health and safety risks.

So, if you have common sense, do not worry. If, like me, you fear your common sense is not the same as everyone else’s, there are hard judgment calls to make to avoid your common sense being tested under the court microscope.