Homeowners face having to pay a specialist to inspect their trees under a safety regime drawn up by one of Britain’s most respected watchdogs.

The British standard for tree safety inspection would require all trees to be checked by a “trained person” every three years, with a still more rigorous “expert inspection” by an arboriculturist every five years.

Tree owners will also be obliged to conduct a “walk-by” inspection themselves once a year.

The drive to make all trees subject to inspection is being led not by the Health and Safety Executive - which opposes the move - but by the British Standards Institution (BSI). Highly respected in the building and engineering industries, it is better known for its views on the composition of cement than on the health of trees.

Its proposals come despite the low risk posed by trees to the public. On average six people a year are killed by falling trees, making the probability of a fatal accident less than one in two million. This compares with 647 deaths from tripping down stairs or steps.

Under the health and safety principles that have governed trees for 60 years, the risk they pose is “tolerable”, and no inspection regime is necessary if the probability of death is less than one in one million each year.

But the BSI was prompted to act after several legal cases appeared to challenge the existing regime. In 2006 Gary Poll, a motorcyclist, collided with a fallen branch on a road in Somerset and made a claim against the landowners. The judge ruled that if arboriculturists had been called in, the accident could have been averted.

But critics say that the BSI is overreacting and fear that a tree standard would spawn a new industry of tree inspection - a bonanza for arboriculturists but extra cost for homeowners, local authorities and landowners.

Many tree surgeons do not currently charge to inspect garden trees because it normally leads to work. Tree Care, a company in West London, is typical. It does not charge for inspections and quotes but the charge for the most basic work is £160. However, some companies who work for large landowners do offer an inspection service. Prices start at £300.

However, those consulted by The Times yesterday said that if they were being called out for numerous routine inspection visits they would have to charge about £70 a time, or more if they had to climb the tree.

The tree standard is currently a draft, subject to public consultation, but many tree owners are not sure how to make their views known.

The new British Standard would cover trees growing anywhere near where the public had access, or within falling distance of man-made structures such as other properties. It also covers areas where “branch shedding or whole tree failure could potentially cause severe harm or loss of life”.

A recently established risk watchdog, charged with halting the march of the “nanny state”, has intervened to try to get the BSI to think again. The Risk and Regulation Advisory Council said that the level of risk posed by trees did not warrant a national inspection regime.

“The risk from trees has not increased. We believe the existing legal principle effective for the last 60 years is sufficient,” Rick Haythornthwaite, the council’s chairman, said.

“This is a perfect example of how the pressure to regulate to minimise public risk can lead to wholly undesirable outcomes if left unchallenged.”

He also accuses “risk entrepreneurs” in the tree industry for seeking regulation to maximise the perception of risk. “The result is a set of standards for which they are perfectly placed to provide profitable solutions,” he said.

A spokeswoman for the BSI defended its decision to set standards for trees. “We issue standards in all sorts of areas, including businesses such as estate agents,” she said. “We hope to issue the standard early next year and everyone is able to comment on the draft up until July 31.”

Anyone wishing to comment on the draft standard can do so by visiting drafts.bsigroup.com.

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