Scores of construction staff working outdoors were diverted to interior work this week as stormy weather made some building sites unsafe.
Fletcher EQR spokesman Barry Akers said the organisation was monitoring conditions in Christchurch, but operations were still under way.
He did not know whether every contractor Fletcher EQR used in the city was still working as contractors were in control at individual homes.
If contractors decided to stop work they would be empowered to withdraw their staff, and Fletchers would support that, he said.
Fletcher EQR had about 1100 contractors in the city, and while it was not known exactly how many staff each employed as that number could vary from day to day, it estimated five staff per contractor, which meant a work force estimate of 5000.
In addition, Fletchers had about 700 staff, who were all fully employed today, he said.
Leighs Construction operations manager Graeme Earl said the weather had meant work on the company's external sites had been limited for the health and safety of workers, but staff had been redirected to internal work.
Outside work had been affected since Tuesday, he said.
Leighs employs 92 construction staff, not including subcontractors and management.
The Christchurch Hospital upgrade had soaked up most weather-affected staff, and several other fitouts had benefited from bolstered staff, he said.
"We try to accommodate them where possible, as everyone does." It was business as usual, albeit in the grip of winter, he said.
"At the end of the day, it benefits the internal projects by having an additional work force."
He said the main external projects in hibernation were the visitor centre in the Botanic Gardens, the three-storey Strange's building replacement at the corner of High, Lichfield and Manchester streets, and rebuilding at Rangi Ruru Girls' School.
Hawkins Construction South Island regional manager Steve Taw said the cold weather and snow were just part of Christchurch winters.
"It's what we're used to in Christchurch. We're a hardy bunch in this industry."
Hawkins employed more than 100 construction staff, plus subcontractors, spread across the city, he said.
Hawkins had a dedicated project team to support insurer IAG in its repair and rebuild of homes and offices.
Workers would be transferred between sites when it was feasible, he said.
"They dress up warm, rug up warm and sometimes they prefer it was too cold than too hot," he said.