Work Safety Commissioner Mark McCabe said seven businesses - including Croissant D'Or, East Bar and Grill and Iori Japanese Restaurant - had been cleared on Saturday and were free to trade, after the Pancake Parlour and Barracks Internet Cafe received the first WorkSafe ACT clearances on Friday.

Mr McCabe did not have full details when contacted on Sunday, but said all businesses who had sought an immediate reopening had been approved on Saturday.

"There's probably about another 10 looking to be cleared this week," he said. "It could be about 10-15 [further businesses] where they're facing a longer period.

"There is a fairly big chunk of the building which needs a bit of work to ensure it's structurally sound - my guesstimate is that is probably 40 per cent of the building."

He said the recovery process had occurred quickly because the government accepted his advice to invoke emergency powers to protect public safety, allowing them to engage a contractor, who completed the tasks on Friday morning.

Economic Development Directorate director-general David Dawes said ACTION had restarted bus services along East Row in the City Interchange on Saturday.

Verity Lane has been reopened for vehicular access, and pedestrian access has also been established linking London Circuit to East Row.

The building, built in two phases from 1926 to 1927 and 1941 to 1946, was evacuated after last week's fire, which is thought to have started in the Coo Japanese restaurant.

Mark Ryan is the owner of Krave/Clubhouse, one of the businesses cleared to reopen on Saturday. He said the ACT government had worked quickly to ensure minimal disruptions while reducing safety risks to the public.

“I think a lot of the WorkSafe guys and others – the police were involved I guess - I think they’ve done a damn fine job and deserve a pat on the back,” Mr Ryan said.

“[Government] allowed public access for their communications through their systems – it was very transparent what they were doing and when they were doing it.

The night club owner said his business – on the Alinga Street side of the Sydney Building – had not suffered any physical damage, and “a couple” of thousand dollars had been spent on getting the required electrical and plumbing checks done.

Mr Ryan said patron numbers at the venue he had owned for more than 10 years were lower than usual on Saturday, with expectations the building may have been closed and the Royal Canberra Show likely causes.