If you take out a mortgage, it is obligatory. In other cases, it is up to youwhether to insure your property or not. It is a common practice to insure a flat or a house, as well as  contents both inside and outside the property, to avoid a lot of problems in the future.
A standard insurance in the UK is valid for 1 year. We recommend you not to hurry when the time comes to prolong it. You should talk to your insurance broker to discussbetter insurance plans that you can benefit from.