Canberra's workplace compliance watchdog issued the shut downs after it inspected 13 of the company's residential construction sites. WorkSafe ACT has not named the company.

Inspectors found more than 50 offences across the 11 sites shut down. WorkSafe ACT said it was carrying out investigations.

The sites that were shut down had been found to have serious safety breaches and the company has been prohibited from carrying out all construction work in the ACT until the issues were fixed.

As well, the company is required to implement a safe work system.

"Our inspections found too many issues at the 11 construction sites, including fall from height risks, site security, lack of housekeeping and electrical safety issues," WorkSafe ACT acting work health and safety commissioner Amanda Grey said.

"This lack of safety is unacceptable. Every worker has the right to work in a safe environment and go home to their families at the end of the day.

"We're committed to improving safety standards in residential construction to help prevent workplace deaths and injuries in the ACT."

The Canberra Times asked WorkSafe ACT if it could provide the location of the sites and whether the sites were high-rise or single residential but a response had not been received before the time of publication.

The shutdown came after WorkSafe conducted a safety blitz at the start of the year that saw more than 70 sites closed.

This investigation was sparked after two workplace deaths at separate buildings sites in Denman Prospect.

In January, a 47-year-old died at an under-construction townhouse complex after a pallet of roof tiles fell on him. In February, a 60-year-old man died after falling from a construction site.

WorkSafe ACT became an independent regulator in July.

This followed a review in 2018 that recommended the watchdog be operated independently.