A deal for the West Wing of Patshull Hall at Patshull Park, Burnhill Green, is understood to be imminent, after the prospective owners submitted plans to install a lift across its four floors in order to negate the need for major renovations.
They say the development will "future proof" the Grade I-listed Georgian mansion for their later years.
A planning application under consideration by South Staffordshire Council says the applicant is in the process of completing a deal for the pile.
It underwent a full restoration in 2009 and was recently listed by estate agents Savills as "under offer" with a guide price of £1.25m.
A planning statement submitted on behalf of Yvonne Landau, says: "The lift will be convenient and a stylish addition in what is a very vertically arranged house and, therefore, is an asset.
"The applicant is active; however, the property is on four floors, and providing the lift now will negate the need to create a bedroom and bathroom on the ground floor at a future date and retains the property to be used in the way it was designed, with very little impact on the historic fabric.
"The applicant is therefore have taken decisive action to prepare their home in case their mobility becomes more difficult in the future.
"The installation of a lift will improve the functionality and future life of this protected listed building with little impact to the historic fabric, whilst maximising the lifestyle of the applicant.
"The works will be carried out sympathetically using appropriate construction techniques and materials sympathetic to the structure and fabric of the building."
It added: "In conclusion the chosen location for the lift will have no impact on original fabric or historic fixtures and fittings."
The West Wing was built around 1750 by James Gibbs and for more than a century was owned by the Earls of Dartmouth.
The estate surrounding Patshull Hall was put on the market in 2018 for £32.5 million.