Barn conversions to dwellings will be “economically unviable” for farmers in the Brecon Beacons National Park after the authority voted to apply hefty charges.
The park authority, which also acts as the local planning authority, voted to increase charges on barn conversions sold on the open market to 58% of their estimated value.
This, warned the CLA, could add costs of £100,000 to the average barn conversion, making most projects economically unviable.
Instead, the authority should apply a universal test to ensure the charges did not stop conversions going ahead, said the CLA.
Wales has a different planning system to England for converting agricultural buildings into residential dwellings and does not use permitted development rights.
Barn conversions in Wales must first meet criteria for affordable homes or commercial use. If they fail on this, the farmer-landowner can demonstrate that the converted dwelling needs to be sold on the open market, but must pay a charge.
However, converting an agricultural barn into a dwelling in the countryside could cost two to three times more than a new build in town, claimed Karen Anthony, policy director at the CLA Wales.
This made many barn conversions unappealing to developers and local authorities for affordable housing, said Ms Anthony, which meant farmers looked to convert for the open market.
But with the increase in charges, this option was now looking unviable too, said Ms Anthony.
She pointed to one CLA member, who had applied for conversion of five barns to dwellings last year and accepted that they would have to pay the £130,000 levy to create non-affordable homes.
Following the ruling by the Brecon Beacons National Park, the charges now stand at £480,000, which make the conversions unworkable.
The increased charges would have an impact on “the fragile rural community of Wales”, said Ms Anthony, as they would deny farmers additional income, which she said was usually invested back into the business and the local economy.
Wales has 25 local planning authorities – 22 national authorities and three national parks.