Plans to transform a mansion in Richmond into a huge private school for up to 1,000 pupils with a swimming pool, forest school and theatre have been revealed. 

Radnor House will move its senior school to Kneller Hall in Twickenham from September 2023 if the major redevelopment of the 30-acre site goes ahead.

Radnor House charges up to £7,430 per term and would expand under the “state-of-the-art” proposals.

Dukes Education owns Radnor House and bought the Grade II listed mansion from the Ministry of Defence in September 2021.

The estate was home to the Royal Military School of Music for almost 170 years.

The house was originally built in the 1700s and backs onto Twickenham Stadium.

The former Ministry of Defence building would be renovated under the plans, and a new three-storey teaching block would be built on the grounds.

The guardroom would be converted into a music centre while the band practice hall would be turned into a 275-person theatre. 

New sports facilities would be built on the site, including a sports hall, swimming pool and sports pavilion.

There would also be tennis courts and football, hockey and rugby pitches.

A shelter for outdoor lessons would be built on the grounds, known as a “forest school”.

Dukes Education says Radnor House, based in Pope’s Villa, is “heavily oversubscribed”.

The proposals would allow students from year seven and above to move to Kneller Hall, while the Pope’s Villa site would become a prep school.

The school would accommodate around 750 students, with capacity to grow up to 1,000 students. 

A public exhibition on the plans at the mansion last week was attended by more than 100 locals. 

In a statement, Dukes Education said it wants to retain the site’s “historical musical legacy”.

The organisation said the move would create up to 110 jobs and has pledged to allow locals to use the proposed new sports facilities. 

The statement said: “At the heart of the Whitton community we are keen to build a good relationship with our neighbours and ensure that the local community is able to benefit from the facilities at Kneller Hall, particularly young adults and families in the Whitton area. 

"We will be working with local primary schools to identify children to benefit from a full or partially funded Kneller Education.

“A draft community use agreement will accompany the planning application. The school will work with the council’s sports development team to provide a range of opportunities for local community groups and schools to benefit from these exciting new educational and sports facilities.

“Much of this access will be during the weekends and potentially weekday evenings during the summer.

"We are also engaging with Sports England on the proposals.”

Dukes Education is set to submit a full planning application to Richmond Council this autumn.