Landlords and developers in parts of Nottinghamshire are being warned to secure their properties after a spate of burglaries.
Police said there had been 78 break-ins at empty and new-build properties in Broxtowe, Gedling and Rushcliffe over the past six months.
Copper piping, radiators, boilers and white goods have all been taken in the burglaries.
Owners of larger buildings have been advised to hire security guards.
South Nottinghamshire crime reduction manager, Peter Ainley, said: "Historically such offences have always occurred but with an increasing world shortage of metals, the number is increasing."
Mr Ainley added: "Often the damage the thieves cause while forcing entry to properties exceeds the value of the items they steal.
"When this figure is added to the replacement value of items stolen, it can be quite significant."
Other recommendations to prevent the burglaries include installing burglar alarms and using SmartWater to mark items which can then be identified if they are stolen.