A report to Cotswold planners reveals an urgent need for underground repairs to the National Trust's Newark Park, near Wotton-under-Edge, with areas of the historic home's basement being shored up by temporary steel posts to combat the risk of collapse from rotting timber lintels.

The bid to repair the Grade 1-listed Tudor hunting lodge, which was built in 1550 by Sir Nicholas Poyntz, an influential English courtier to Henry VIII, comes as the NT celebrates 75 years since the property. A care home until it was bequeathed to the nation, the estate was gifted by the wealthy Clutterbuck family in 1949. 

Since that date, the venue near Wotton-under-Edge has become a magnet for Cotswold visitors and is described by the Trust as "a secluded estate with glorious views, providing country house hospitality, garden strolls and woodland walks".

In 2008, rooms in the main house and locations outside on the estate were used by the BBC in 2008 when it filmed a TV drama version of the Thomas Hardy classic, Tess of the D'Urbervilles, which starred former 007 actress Gemma Arterton in the eponymous role. 

More recently – as exclusively reported by Punchline-Gloucester.com – the property has been at the heart of speculation amid local claims that the 750-acre estate is in line for rewilding as part of a national policy for the Trust to become carbon net zero by 2030.

In the wake of a severe storm six years ago, the Trust embarked on a program of extensive and complex repairs and restoration at the property after frozen pipes burst in the roof, sending water cascading down into lower levels. The NT said at the time that costs were "significant".

The latest issue has now been indentified in the vaults of the building, near the scullery, Tudor kitchen, wine cellar and old bakery. A report told planners at Cotswold District Council that a doorway to the passageway that leads to a wine cellar has been shored up with temporary Acrow props "to support the masonry above", while the props restrict access to the area beyond.

The report added: "Other masonry areas where embedded timber has decayed or mortar is missing/cracked have not currently been supported, although some of these may require temporary propping in the near future.

"Visitors to Newark Park House are generally kept out of the Engine Room and Passageway due to the wet environment and the uneven steps and floor. Prior to the discovery of the decayed lintel above the doorway into the Passageway, the door was opened up so that visitors could at least peer into the spaces. Once the long- term repair has been completed, this practice can begin again. However, due to the uneven steps to the Basement area, it will not be possible for visitors with mobility issues to visit the Basement in the foreseeable future."

Usual NT repair policies are for like-for-like materials use, but the Trust is seeking a stronger remedy in this instance, requesting "reinforced cast concrete for the doorway, pre-cast concrete for the small cellar opening and clay tiles for the north wall. This is due to the very damp sub-terranean environment and the high risk that this will result in rapid timber decay once more."

An extensive engineer's report by Bath-based civil and structural engineers Mann Williams also identified a hidden room in the basement of the building.