Damien Flores, superintendent, and Brian Potter, superintendent and safety lead, work on the renovation of the Tucson Convention Center on Aug. 29, 2014. The $7.8 million facelift included new upper seating, sound panels, lighting and ceiling tiles.

Rio Nuevo has a $55 million wish list for high-tech upgrades at the underused Tucson Convention Center to make it more appealing to meeting groups.

But Rio Nuevo doesn’t know where it will find the money to do the projects.

The Rio Nuevo board met at the convention center Thursday in a room board member Mark Irvin called “antiquated.” It has heavy floor-to-ceiling drapes the color of pea soup and pale mauve-colored walls.

Now that Rio Nuevo is wrapping up a set of TCC projects that included new arena seats, concessions and bathrooms, the board is considering future phases.

Rio Nuevo hired a consultant to draw up a detailed list with cost estimates that total $55 million.

“We’ve actually asked them to go ahead and identify anything that might contribute to making this facility more competitive, even though we knew going into it that a lot of it is something we certainly cannot afford,” chairman Fletcher McCusker told the board.

The first few projects — those most urgently needed to attract meeting business — would cost about $10 million.

Those Phase 2 projects would include $4.3 million to remodel the ballroom and “bring it up to 21st century technology,” said consultant Phil Swaim.

About $1.3 million would be spent to renovate what McCusker called “disgraceful” restrooms. Another $3.4 million would create a conference center with a high-tech board room, and another $1 million would upgrade the arena’s locker rooms, dressing rooms and green rooms.

The improvements need to be good enough to draw in meetings and conventions from other cities and not just shift existing meetings from other Tucson-area hotels and casinos, said board member Chris Sheafe.

The next step is to talk to the city about how it will help pay for the improvements, McCusker said.

Thursday’s meeting was the first time the proposal was made public, and city leaders haven’t seen it yet.

With the sale of the arena site next to the TCC to a hotel developer and the sale of the Rialto Theatre to the Rialto Foundation, Rio Nuevo will have about $6 million next fiscal year, he said.

Rio Nuevo also has about $7 million in the bank, but some is committed to other projects, McCusker added.

“You can see how tight it would be if we tried to do all of Phase 2 ourselves,” he told the board. “It would take 90 percent of the dollars we have available in the near term, and that would make it really challenging to look at any other projects.”

And there’s no way Rio Nuevo could move into Phases 3 and 4 without either getting matching funds from the city or issuing a bond and increasing the city’s rent to pay it off, McCusker said.

The city has been paying about $1.4 million a year for rent, which is less than half the annual rent it paid from 2002 to 2012, he said.

Phase 3 includes $6.1 million to upgrade the exhibition hall, $11.8 million to add meeting rooms, and $2 million to add premium seating to the arena.

Phase 4 is an $18 million parking garage that would be built on the existing parking lot at Granada Avenue and Cushing Street.

Contact reporter Becky Pallack at bpallack@tucson.com or 573-4346. On Twitter: @BeckyPallack