PLANS for a home gym and swimming pool at an historic site visited by royalty have been approved – despite a dispute over a greenhouse.

An application for permission to build a gym and a pool house with a car port at the grade-II listed mansion was almost derailed by homeowner Andrew Blowers’ refusal to give up a greenhouse built without planning permission.

Mr Blowers’ Great Campston mansion dates back to the 17th century and the site’s history to medieval times with connections to both King Charles I and Welsh prince and warrior Owain Glyndwr.

The homeowner applied for permission to build the gym and pool in its grounds of his historic property in Grosmont, near Abergavenny, in April last year, as well as listed building consent.

The house, which dates back to the 17th century but has since been remodelled and enlarged notably in 2002, was listed in 1952 while a barn in the grounds was grade-II listed in 2002 and there is still a working farm on site.

Monmouthshire County Council’s planning department considered rejecting the application due to the greenhouse that was built without planning permission.

However it relented and said despite its failure to have the greenhouse removed from the land, and from the plans submitted with the application, it would grant the permissions – but with a condition stating the greenhouse isn’t covered by the planning consent.

Planning officer Kate Bingham, in a report, described the greenhouse as “domestic, modern and highly reflective” and as such said it is “particularly detrimental in the setting of the listed buildings”.

The report stated though the greenhouse will remain in place it isn’t covered, or approved, by the application: “It has been considered objectionable and although lengthy negotiation for its removal on plan and in physical form has failed to reach agreement, it will be conditioned that notwithstanding the application, ‘a greenhouse is not consented as part of this consent’.”

Despite this it was decided the application, which also covers the change of use of a 226 square metres of the existing farmyard to residential curtilage to make space for the swimming pool and a new four bay car port, could be approved.

“Consideration to refuse the entire application on this basis was however considered disproportional as this element ‘did not go to the heart of the consent’ in terms of scale or proportion and that a condition prohibiting it would be sufficient,” Ms Bingham said in her report.

During the application the plans were revised and the design for the building “significantly improved” so that it was considered acceptable in “scale, form and design” while evergreen planting, south of the greenhouse, would also “break up” views with other biodiversity enhancements also included.

A public footpath runs along the driveway south of the site which had been one of 17 monastic granges belonging to the Cistercian Abbey of Abbey Dore. Following the dissolution of the monasteries, in 1536, it was granted to John Cokke of London before it was acquired, in 1600, by John Pritchard, a notable figure in the history of Grosmont.

More than 200 years after Glyndwr was defeated at the site the house, which is now at the end of a 450 metre private drive, was visited by King Charles I in 1645 on his way to Raglan after the Battle of Naseby.