Police are investigating a burglary and theft of tools and machinery which took place at the Persimmon Homes site at Carleton Meadows in Penrith.
The burglary occurred overnight on Thursday 18 to Friday 19 April.
A Cumbria Police spokesman said: “Offenders using one or two vehicles have entered the site and broken into containers and offices and have taken heavy items away in a vehicle which would have left Carleton Meadows, travelled down the Parklands onto Oak Road.
“Witnesses are asked to report times and descriptions of any large vans that used that route overnight so they can be traced or eliminated from enquiries.
“Local builders are advised to ensure they have adequate security on their sites and are welcome to contact police for advice.”
Anyone with information is asked to contact PC1728 Nigel Hamblin on 101 or Crimestoppers on 0800 555 111.
