TATA Steel has submitted plans to convert its renowned research base in Rotherham into an estate of 127 homes.
The firm is to close Swinden Technology Centre, at Moorgate, and relocate the operation to Warwickshire.
Grade II-listed Swinden House will be split into 13 flats while Sitwell House, the workshops and former gatehouse are also to be retained and converted.
The remaining lab and office buildings - added between the 50s and 80s - will be demolished to make way for a mix of new properties.
A spokesman for agents Harris Lamb said: “The scheme will offer a spread of family accommodation, from one-bedroom apartments to five-bedroom dwellings.”
Swinden House was built by solicitor Thomas Badger between 1878 and 1880 and used by the National Fire Service during the Second World War.
It has been used for steel research for more than 60 years.
Tata said all 135 staff would be offered relocation when closure was announced in 2014.
The plans announced last year - include a new access from Beaconsfield Road.
They have been welcomed by heritage campaigners but concerns about parking have been raised.
One resident said: “Beaconsfield Road is a bus route and used by ambulances and visitors to Rotherham General Hospital.
“Parking charges at the hospital have caused a large increase in the number of cars parked along the road and this has made access and on-street parking for local residents difficult.
“Has any consideration been given to the impact on residents of heavy construction plant using the road while the work is ongoing, and what measures will be taken to accommodate the additional traffic once the development is complete?”