A DUP MLA's triple garage which he claimed didn't need planning permission contains office space, a printing business and an upstairs floor with a personal gym, pool table and bowling mat.
Trevor Clarke submitted retrospective plans for the garage at his rural two-storey home after facing enforcement action from council planners.
Drawings lodged with the council now reveal the scale of the structure which Mr Clarke, who has a sideline planning advice business, had previously insisted did not require planning approval.
The huge garage, which has three separate garage doors and a pitched roof, has been under investigation for alleged planning breaches for a year-and-a-half.
Mid and East Antrim council has also been examining a printing business, AC Print, which is run by Mr Clarke's son from the address without planning approval.
The family also run a car sales business from the address outside Randalstown.
Mr Clarke's planning application seeks retrospective approval for a "domestic garage and office for car sales and printing".
The garage has three roller shutter doors for vehicles, plus a separate fourth door to access a general office space and area for printing equipment.
It has a downstairs window beside the office door and an upstairs window on the gable wall.
There is also a staircase to a second floor in the roofspace, which has enough room for a gym, pool table and a "bowling mat".
According to the planning documents, the floorspace has 20m sq for office use, 10m sq for production and 10m sq for storage.
Mid and East Antrim council said an investigation some years ago had found the use of the land for car sales was "immune from enforcement" due to legislative time limits.
But an enforcement investigation was opened in August 2018 after the garage was discovered following a fresh planning complaint about the car sales business.
The planning application shows Mr Clarke began seeking retrospective approval in September last year, just weeks after The Irish News revealed the ongoing enforcement probe.
However, files were only made publicly available online recently as the council had been seeking further information.
According to guidance on the Planning NI website, planning permission for a detached garage is not required if its maximum height is four metres; the area covered by it and any other outbuildings is not more than half the total area of the house; and it is used solely for domestic purposes.
When the enforcement probe first publicly emerged, Mr Clarke maintained that planning permission was not required.
A DUP spokesman for Mr Clarke at the time said: "Planning permission is not required for a detached domestic garage if it meets certain conditions.
"Mr Clarke's view is that the garage on his property meets these, despite a complaint submitted by a political rival."
But the South Antrim MLA submitted retrospective plans after discussing the issue with council officials.
The garage probe is among several controversies which emerged last year surrounding Mr Clarke and his wife, DUP councillor Linda Clarke.
In July, an Irish News investigation revealed the Clarkes' sideline planning consultancy business.
Mr Clarke has rejected concerns that Versatile Consultancy breaches assembly rules which prohibit paid advocacy.
Mrs Clarke is also being investigated by a council standards watchdog after it emerged she was involved in awarding more than £4,500 in council contracts to her son's printing business.
The couple have insisted they "made all the relevant declarations and adhered to all rules".
