Normally your solicitor will submit a search (covered by the Local Land Charges Act 1975) to the local authority directly before you purchase a self build plot or a property. This will include standard questions about various item such as previous planning permissionthe legal basis for being allowed to do some form of development such as building a house. (not to be confused with Building RegulationsThese are the mass of regulations that cover safety, health, welfare, convenience, energy efficiency etc. in the way buildings are constructed. Not to be confused with Planning consent (which is more to do with whether you can put up the building in the first place) which are all about whether the building is properly constructed). see more on Planning the legal basis for being allowed to do some form of development such as building a house. (not to be confused with Building Regulations which is all about whether the building is properly constructed). see more on Planning, adjacent roads, rights of way, water, drains etc. Many local authorities are making this type of information available on the web or at their offices.
UK Home Information have useful details on what the searches cover. However you may want to get hold of information at an earlier stage. For example you may suspect that the area is prone to flooding or contamination and there is no point in going any further with plans to purchase. This is when you could contact a surveyor and ask them to look into specific areas of concern. See pre-purchase land survey