Number 98 was leased by Lone Star while the chain's building on The Strand was demolished and rebuilt. Lone Star moved back to The Strand last year and the building had been empty since.
Mr Jones said the decision to demolish the buildings was made because they had a range of issues, including low seismic ratings. The issues meant the buildings were not viable for strengthening works or suitable for lease.
The site has been identified for some years as a redevelopment opportunity but previous schemes had not progressed, he said. "We are currently working through the long-term redevelopment options for this site.
"The temporary pop-up park and car parking spaces means that instead of empty shops, we'll have a communal area and additional car parks for our city centre until the land holding is developed."
Work on the new space began last week, with contractors preparing the building for demolition. Fencing will be in place during redevelopment.
The project is part of a number of measures to increase the number of car parks in the city centre until more permanent investment in a car parking building is made.
The council expected the new communal space to be ready by December.
The new parking spaces will mostly be pay and display, and some of the existing pay and display spaces to the rear of the car park would be leased.