He said it was too early to determine where it would re-open but he was certain it wouldn't be on Eat Streat.
"We are fine dining and it's too noisy down there. People come here specifically for the quiet."
The restaurant, which has won a New Zealand Beef and Lamb Excellence Award for 16 years in a row, is normally open on Tuesday nights but Mr Gray said they decided to close for the night because he needed the staff to work an event at the Black Swan Hotel.
"We definitely think it is a blessing for us because it is normally open at night."
Mr Gray said he had owned the restaurant for just two years so wasn't particularly attached to the pre-1920s building, but his staff, locals and regulars were.
"Kim Jones, one of our managers, has worked here for 11 years and she is really upset. She puts her heart and soul into this place."
Fire safety investigator Stuart Bootten said about 12 firefighters and five support crew, plus the acting area manager and himself were at the fire. It took about 20 minutes for the fire to be controlled.
People in nearby buildings were evacuated, including Reading Cinema across the road.
Mr Bootten said the main damage was to the back end of the building and roof void, and there was heavy smoke damage throughout.
He said four appliances had been plugged into two multi-boxes, including three fridge/freezers and a fan.
"The current draw can heat up the multi-plugs without tripping the safety switch because that is just for a short. It continues to heat and if it isn't ventilated, as this one wasn't because there was a tea towel up against it, you get no ventilation, continued heat, fire."
Professionals McDowell Real Estate co-owner Melanie Lovegrove said one of their staff members texted her last night and told her there was a fire next door to their building.
She said they were "freaking out" in case their building caught fire too.
Mrs Lovegrove said her husband, Steve, raced down and found the street cordoned off and people everywhere.
"We feel very sorry for the restaurant owners."
The building's owner, Ian McDowell, did not want to comment.
Safety tip
• Use multi-boxes as they are intended
• Only plug in low current electricals, such as lamps, phone chargers and computers
• Electricals that have heating and cooling systems such as ovens, fridges and microwaves use more power
• Make sure the multi-boxes are ventilated/in open areas
- Rotorua fire safety investigator Stuart Bootten