Whether or not you decide to take out home insurance it is entirely up to you. There is no law enforcing this, (unlike car insurance), however unless you can afford unexpected bills, it is well worth considering. Home insurance can cover you from damage such as flooding, storms, and theft. It can also cover against accidental damage to any of your belongings.
In a lot of cases, your mortgage lender will insist that you insure your home. This protects the lender should anything happen to the house, they would get the money back they lent you through the insurance.
It is not normally necessary to keep with the insurance that you took out with your mortgage unless you agreed a deal when taking out your mortgage. If you are not tied to this insurance, you may well be able to make significant savings if you do some research into other Insurance policies to find the best deal.