London's only polo club has lost a battle to extend its arena next to a 17th-century mansion on the banks of the River Thames.

The planning inspector has dismissed an appeal from Ham Polo Club, based next to Ham House, following Richmond Council's earlier rejection of its plans to build an arena extension for winter sports.

The club originally submitted plans in 2021 to extend its small sand arena to host winter polo, along with riding lessons and training horses, with a new 1.5-metre timber fence around it. However, the club is in the Ham House Conservation Area and on Metropolitan Open Land (MOL), which means development should not be approved except in very special circumstances.

It was historically part of the Grade II* listed gardens and pleasure grounds attached to Ham House, which was built in 1610 and continues to be a popular attraction.

The council's planning committee defied officers' recommendations in February last year to reject the scheme, with a report on the decision arguing it would have an 'urbanising impact and appear as an alien landscape feature uncharacteristic of, and causing harm to the gardens, pleasure grounds and conservation area'.

The application also received 213 objections from the public, with particular concerns it would negatively impact the historic surroundings and block views across the land.

Existing view from the entrance to the polo club. (Photo: Ham Polo Club via Richmond Council)

Lodging an appeal with the planning inspector over the council's decision, the club argued in a statement the scheme was appropriate development in the MOL that would not affect its openness or 'represent an urbanising or alien feature or materially affect tranquillity'. It said it would plant new hedgerows and trees to 'soften the appearance' of the proposed fence.

A further statement added: "The club currently uses the existing small arena for horse jumping/riding lessons, but the uses are restricted by the arena's inadequate size.

"An extension to the arena, as proposed in this application, would be of massive benefit to the club and the community by safely facilitating a much broader spectrum of uses, including winter polo, riding lessons in the winter months, schooling for lunging/dressage and jumping for non polo."

Planning inspector Helen O'Connor ruled in a report the extended arena would not be inappropriate development in the MOL. She said the main benefits of the scheme would be the club hosting more polo and other activities, along with creating more jobs.

However, Ms O'Connor said the fence enclosing the extended arena and its level surfacing would be an 'obviously man-made engineered incursion into the historic landscape'. She added winter polo is fast-paced which, along with increased activity at the arena under the proposals, would disturb the tranquillity of Melancholy Walk, which runs next to the site.

Ms O'Connor concluded the proposals would negatively impact the 'important green and tranquil qualities' of the gardens and pleasure grounds and, in turn, harm the conservation area.

She wrote: "Overall, given this particularly sensitive context, I am not persuaded that the sum of public benefits would outweigh the harm. Consequently, the proposal would conflict with national policy to protect the historic environment."

Ham Polo Club has been contacted for comment.