Obtain a 1:50,000 'Discovery Series' Ordnance Survey map with both the location of your new generator and the site boundary clearly marked with a red pen.
You will also need a detailed site plan, in the appropriate scale, of the proposed facility, indicating the site boundary, the proposed location of the connection point, generators, transformers, site buildings etc.
A draft electrical single line diagram of the proposed facility detailing all significant items of plant and their values including Relevant Voltage Levels, Interlocking, Earthing and Synchronising Arrangements, Relay Types, CT/VT ratios, Generator Transformer(s), Power Factor Correction, Location of Alternative Connections (e.g. house load) and Network Connecting Transformer(s) (if applicable).