The design will include introducing one-way traffic and on-street parking entering from Fryers St and High St, and exiting from Stewart St. Â
Cr Summer said it was wrong not to listen to the ratepayers' most popular design option voted for last year, and council should vote on the matter after the business case is released.
She said she is not convinced it is the best way forward for the mall.
"I don't think we've done enough work in the preliminary discussion about what we want to achieve," she said.
"We've sort of come up with these designs, put them out to the public, they've come back and told us they prefer not having a road.
"We've put that aside and listened to the squeaky wheel of the retailers, who think that a road will improve the sales.
"We don't have a business case and without one it's really hard to make any kind of inferences on what is going to happen if we do push ahead with this.
"We're not likely to go back if the business case says it's not successful. I don't think we should do it blind, and sometimes doing nothing is better than doing something."
All other councillors in the chamber voted in favour of the recommendation.
Mayor Kim O'Keeffe declared a conflict of interest and left the chamber before discussions, while Cr Lee Oroszvary was absent.
Chairing the item during the meeting, Deputy Mayor Shelley Sutton disagreed with Cr Summer's objection.
She said the difference in votes by the public to prefer another design for the mall was minimal.
Cr Sutton said there had been plenty of consultation with the community.
"Something needs to be done with the mall," she said.
"The tenderer comes from Melbourne but he has a local connection.
"Now we've got this going, something will happen in the mall at long last. The traders will be happy and people will be happy. I think it will be very good for Shepparton."
Cr Dennis Patterson said accepting the tender was about "doing it properly".
"What we've got to do is nail the tender document itself and get the design right," he said.
The expected cost of the total redevelopment is $16 million, with the business case expected to be released early to mid next year.