Victorian builders say the state's latest five-day lockdown rules are excessive, especially for regional Victoria where work has ground to a halt just when it was getting back to normal.

Victoria's Premier Daniel Andrews says the statewide blanket lockdown is a "circuit breaker" to a growing cluster in Melbourne's north.

But for Tanya McNamara, whose construction firm has been rebuilding homes in East Gippsland, all the lockdown has done is disrupt the flow of rebuilding after last summer's bushfires.

"Everything's booked and now we're trying to reschedule."

While many have been waiting to rebuild, Mrs McNamara said those who had permission were frustrated by the delay.

"We've got a number of fire-affected properties. They've had hardship enough without this kind of stall as well," she said.

David Jackson was only two weeks away from moving into his new home in Sarsfield, after his property was badly damaged during the fires.

"We're just waiting for the electrician to do the fit off and a few final touch-ups and then we're in," he said.

He said after 13 months of living in temporary accommodation, he was fed up with the decision to down tools.

"Just to sit there and have nothing happening, it's just devastating," he said.

Under the modified stage-four restrictions, construction is not deemed essential work, despite exceptions made in metropolitan Melbourne for construction during its previous stage-four lockdown.

'Little bit ridiculous'

While regional Victoria was under lighter restrictions than Greater Melbourne last year, builders were allowed on-site with masks and social distancing.

Mrs McNamara said the new rules seemed excessive for regional Victoria, especially in Bairnsdale in East Gippsland.

"We sometimes have only one or two people on site at any one time — it does seem a little bit ridiculous for us," she said.

There was also confusion for renovation businesses on Friday.

Murray Pinnington runs a kitchen and bathroom construction business in Mildura.

He said they were only advised on Saturday morning by the Master Builders' Association that they were not considered essential workers.

"There were several emails on the Friday afternoon saying that they're working on it and they're gonna keep us in the loop and that sort of thing," Mr Pinnington said.

"But there was no clear answer, no definitive answer, until Saturday morning."

Mr Pinnington has eight staff on hold with three projects in progress and another due to begin on Monday, but said they were on standby for any emergency repairs.

"If we get called out for any emergency work, we're just going to play it by ear," he said.

"I dare say all my guys are sitting by the phone waiting for a phone call anyway, so it shouldn't be too hard to find someone."

Making a cheeky reference to professional athletes falling under the category of essential workers, Mr Pinnington took to social media with a photo of a tennis racquet in his tool belt to update his customers of the change.

Horsham-based business owner Dean Hogan said the rule "didn't make sense".

He said he considered it the harshest lockdown so far for the building industry, considering the number of active COVID-19 cases.

Mr Hogan said it halted work on the significant backlog of jobs he had due to the popularity of the HomeBuilder grant scheme.

"In country Victoria, there are a lot of small business operators that often might only have six months of work booked up, but at the moment … I'm a year and a half booked out," he said.

"It's just painful when I know we've got that much work to do."

Concern about 'catastrophic' longer lockdown

Master Builders' Association of Victoria chief executive Rebecca Casson said the restrictions were the harshest the building and construction industry had faced to date.

"For the first time since the start of the coronavirus pandemic, here in Australia our wider industry will be completely stopped," she said.

Ms Casson said all the builders she had spoken to said their workbooks were absolutely full to the brim and any extension of the lockdown could be "catastrophic" for the industry.

"This could have a devastating effect on the future economic recovery if lockdown was to go for longer than five days."

Ms Casson said there were some exceptions for building and construction work to continue such as for road and infrastructure projects and emergency housing repairs.

"You might still see a little bit of building and construction happening and people might be a bit confused as to whether or not they're allowed to go onto work sites or not," she said.

"But those critical infrastructure projects have received very specific exemptions from the Government."

The Department of Health has been contacted for comment.