There are three main types of building surveys:
A valuation survey will assess the current market value of the property. It will usually be carried out by the lender who will require it to underwrite the loan amount.
A Home Buyer Survey and Valuation
This report will assess the value of the property as well as highlighting and defects with the property.
A Building Survey
A building survey is a more thorough assessment of any property defects. It is commonly used for surveying older properties which are more likely to have structural properties or just for peace of mind.
When you have a mortgage approved by the bank you will be legally bound to have buildings insurance. If you own your property out right yourself you do have to have buildings insurance, unless your rent the place out, but it is strongly recommended that you do.