It is expected less than a quarter of construction workers will be going back to their jobs on Monday.
Outdoor sites are due to re-open as part of the Government's easing of restrictions.
The Construction Industry Federation has said physical distancing will mean fewer workers being allowed on-site.
Director Tom Parlon said it will not be business as usual.
"I think we're quite prepared but at the same time on Monday morning it will be an easing back", he said.
"I'd say if we have 20-25% of people back on sites that's about maximum."
Meanwhile, Chambers Ireland says it is relieved the Government has moved to begin the first phase of lifting Covid-19 restrictions on Monday.
Hardware shops and opticians will be among the stores able to open once again.
The representative body's Chief Executive, Ian Talbot says firms will be putting measures in place to ensure there is not a second wave of infection.
"We're very concerned, we don't want to see a second wave that might result in a further lockdown," he said.
"Businesses are very conscious of that and they will seek to manage their environments as safely as they can.
"But we'll need patience, this is going to take some time to get this right, but we really need to get this right."