A call to approve a Pembrokeshire barn conversion so its farmer applicant can fund the urgent conservation of a 19th century model farm and “Gentleman’s Farmhouse” has been refused by the National Park.

In an application to the Pembrokeshire Coast National Park Authority, William Marston, through agent Hayston Developments & Planning Ltd, sought permission, in a resubmitted application, for a barn conversion and extension to create a bespoke dwelling with access and ecological enhancements on land opposite Merrion Court, Merrion, Castlemartin.

A previous 2024 scheme for the barn conversion was refused in early 2025, the resubmitted application intended to address those reasons for refusal, alterations including it being “more sympathetic to its setting, including a reduction in the overall size of the extension,” reducing the visual impact of visual impact of the extension, and reducing the structural demands on the former barn.

A supporting statement accompanying the application said: “The owner is a successful famer in South Pembrokeshire with a modern farm complex at Crackmarren Farm, near Maidenwells. Unfortunately, this building has no use in modern farming being far too small and in an isolated location.”

It added: “Falling within the same ownership is a group of farm buildings, including an abandoned farmhouse, at Merrion Court which is mainly located on the east side of Windmill Lane and south of the application site.

“Approval of this application for a barn conversion is seen as a source of potential funding to enable the conservation and future use of this important example of a C19 model farm, which includes a Gentleman’s Farmhouse.

“This is, indeed, a set of listed buildings that requires a comprehensive assessment and the subsequent preparation of a building conservation strategy. Urgent repairs to roofs are needed in the next 12 months.”

The application includes the offer of a £6,937.50 contribution towards affordable housing.

It concluded: “Whilst the redundant barn is located within an area of Grade 2 agricultural land, it is considered that the impact of the change of use from the perimeter of an agricultural field to a garden for a converted stone barn with small extension, is very limited and that there are successful precedents for such proposals. It is, therefore, considered that the benefits of saving this vernacular building and providing a new dwelling exceeds the loss of land at the periphery of an agricultural field.”

It added: “It is the applicant’s intention to direct any benefit from the sale of the former barn (with consent to undertake the proposed conversion) to the conservation and redevelopment of the nearby Merrion Court complex.

“Previously, PCNP has seen the importance of saving historic buildings that are part of our heritage and we request this can be done again with this more subservient / sensitive scheme.”

An officer report recommending refusal said: “It is considered that the application building is not capable of conversion to a residential dwelling without substantial dismantling and reconstruction, in addition to a significant extension.

“This type of development would be tantamount to a new build in the open countryside which conflicts with all levels of policy that seek to protect the countryside and direct new housing where services are accessible and ecological features can be conserved.”

The application was refused on those grounds.

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