The search for rustic chic 'leaves England scarred'

Conservationists have warned that a rash of botched farm building conversions is contributing to the rapid destruction of England's rural architecture.

Breathing life into a dilapidated barn, byre or stable remains the ultimate in sustainable rustic chic for many urbanites seeking to the swap the rat race for a quieter existence in the shires.

But English Heritage is calling for tighter controls on the rebuilding of old structures after a report published today highlights a plague of poorly-executed conversions that the conservation body complains is scarring the countryside.

It is estimated nearly 10,000 of England's 33,000 listed farm buildings have been converted to residential use, with a significant number of "horror" conversions suffering from ill-suited additions - ranging from Victorian carriage lamps to protruding porches.

The problem is part of a wider loss of irreplaceable farm architecture in England, according to Heritage Counts 2005, a comprehensive audit of rural historical buildings and landscapes.

Nearly 2,500 listed farm buildings in the country are in urgent need of repair at a cost of £30m. There are estimated to be more than 500,000 traditional farm buildings in England, making it the largest category of listed buildings in the country.

The study highlights other losses to rural environment, including the disappearance of half of England's parkland in the past 90 years, replaced by golf courses, motorways and arable fields. The vanished parkland covers 220,000 hectares - an area the size of Warwickshire.

English Heritage said it was reversing its policy of opposing the conversion of historic farm buildings in the hope that more buildings would be saved. But the body warned against the "suburbanisation of the countryside" and said the quality of the conversions needed to improve. It will publish its own guidelines in the new year.

Simon Thurley, chief executive of English Heritage, said: "Almost a third of listed working farm buildings have already been converted and that can do a lot of damage if it is not done with care and attention."

A spokesman for the body added: "We are not against converting these buildings but their character must be taken into account during the design process."

Among the design faux pas outlined by English Heritage is the use of uPVC windows, "pseudo-Georgian" front doors, bright colours on timberwork and large "picture" windows where a wide opening does not already exist.

Instead, converted dwellings should have timber-framed windows, plain timber front doors "with little or no glazing", muted colours on woodwork such as "browns, greys, duck-egg blue, darker greens to enhance the colour of the brick or stone".

The study found that while the proportion of converted buildings was high in some areas, for example, 55 per cent have been converted in East Sussex and some two-thirds of all oast houses are now dwellings, large areas of the country remain relatively untouched.

The Country Land and Business Association (CLA), which represents private landowners, said its members spent an average of £29,000 a year on maintaining traditional buildings that often were redundant.

David Fursdon, president of the CLA, said: "Spending nearly £30,000 a year on buildings that you don't use isn't going to impress your bank manager no matter how cuddly he is."