It is imperitive you have insurance against your property.
One sensible requirement when you take out a mortgage for your new home is that you have a buildings insurance policy to protect your property against things like flood damage, fire and subsidance for example.
Simple extras can include garden damage such as fence cover etc.
When you are about to obtain a quotation, make sure you know:
The period in which your house was buit
The materials your home is made of
The roof type
The house design (semi detatched, detatched, terraced house, flat, bungalow etc)
Previous claims
Wether your house has suffered from subsidence
Wether your house is built on a flood alert area
Visit www.aph.org.uk and follow the links to resources that could help you in your search for a cheaper home building insurance quote.