Collapsed contractor ISG acquired a majority shareholding in ESS in early 2022 but sold it on later that year to parent company Cathexis.
ESS staff took to LinkedIn on Monday looking for new jobs.
One wrote: “Absolutely devastated to be posting this, but me and my amazing colleagues are looking for new roles with immediate effect.”
ESS subsidiary Spatial Initiative is also due to appoint an administrator with an announcement due imminently.
ESS has been in business since 1998 and employs more than 200 people across the UK and Ireland.
It has won places on major frameworks including the Defence Infrastructure Organisation’s Single Living Accommodation Strategic Framework Alliance Agreement, the Army’s Single Living Accommodation Programme and the The Crown Commercial Service Offsite Construction Solutions framework.