Barnsley Council, the applicant for the scheme, outlined its plan for the venue but a total of ten letters of objection - backed by Cawthorne Parish Council - were received during the public consultation.
The Grade II-listed hall and 70-acre estate were sold to Barnsley Council in 1951 by the last member of the Spencer family, Elizabeth, and since then it has been run by the council as a tourist attraction.
It opened as a museum in 1957 and now hosts important collections of glassware, ceramics, paintings and period furniture.
The site has approximately 450,000 visitors per year, with 150,000 people each year visiting the museum itself and participating in a regular programme of visiting exhibitions, workshops and events.
A planning report, which will be discussed on Tuesday by councillors where approval is expected to be granted, said: “The application relates directly to the Spencer Wing, a two-storey stable block located to the north-east of the main house.
“It is listed in its own right and is in a dilapidated condition. The ground floor is currently used for storage and the interior contains many original fittings, including the former tack rooms and stable accommodation, which are in a substantially intact but poor state of preservation.
“The works would involve the conversion of the current western stable to a cafe at ground floor level with an overspill area and shop above at first floor level, and a lift and staircase connecting the levels.
“The proposals would allow visitors to move through the covered walkway to the north of the kitchen courtyard via a new glazed porch and into the cafe area without visitors entering the larger courtyard to the north.”
Cawthorne Parish Council object to the scheme, saying the design of the glass porch isn’t ‘aesthetically pleasing’, while residents claim the proposed 11pm closing time would be disruptive.
However, planning bosses have recommended it to be approved, with the report adding: “The proposals constitute minor external additions and internal alterations to the Spencer Wing.
“The works are supported by Historic England and the council’s conservation officer and should have no significant impact upon the Grade II-listed building or its setting.”