If you insure your contents with the same company as your buildings you will probably be covered for a minimum amount, �30,000 is not unusual. Have a good look around your house and add up the cost of each item - not forgetting carpets, curtains, bedding etc. If you are underinsured the company may average your claim. That means if, say, your contents are worth �50,000 but you have insured them for �25000 you will be deemed to have accepted half the risk. So if you have a claim for, say, �1000 you will only be paid �500.
Better to be overinsured a little than underinsured.