A historic Herefordshire farmhouse is being readied for use as a film set next month – but details of the film and its stars remain under wraps.

A planning application seeks permission to use Cwmmau Farmhouse, a remote National Trust-owned property near the Welsh border between Kington and Hay-on-Wye, between July 5 and August 22.

Herefordshire Council received the application on June 28, validated it on July 2 and began consulting on it on July 23. It aims to determine the application by August 27.

The application has been made by L Powell of Rowan Tree Films, of which little is known.

But the name coincides with Rowan Tree, which extras casting agency Key Casting described last month as “a feature film from Oscar-winning director and producers, it is the film adaptation of a well-known best-selling novel”.

Key Casting was looking for extras locally, particularly those with “experience or skill in a trade”, for filming in Herefordshire and Gloucestershire this summer.

The planning application also seeks permission for a “unit base” for the eight-week period at Little Penlan Farm on Apostles Lane some distance away.

“Most activity will take place during the later preparation phase and filming phase, which will take place over six days through the early-mid of August,” both inside and outside the farmhouse, it explains.

Normally offered as a holiday let, the grade II* listed farmhouse and adjoining cowshed, along with a grade II listed granary, date back to the 1600s and “have been specifically chosen as they closely match the requirements of the production”, it adds.

And while there will be some extra construction within the farmyard, this will be “temporary and reversible”.

Herefordshire Council has a policy to “to assist film and television production” in the county, the application points out.

Comments on the application can be made until August 22.