This document draws together work undertaken as part of Work Stream 2 of ITRC, specifically looking at the data and processing requirements to build national infrastructure networks. The purpose of the document is to give an assessment of the national infrastructure networks that need to be constructed and identifies which datasets collected within the National Infrastructure Asset Database can be used to represent different features of the different networks. Furthermore the document identifies where data is missing, whether that is missing spatial, attribute or connectivity data for each of the networks. The document then suggests a series of spatial processing steps required to be undertaken to create topologically valid representations of the national infrastructure networks, based on the data identified as being the building blocks of that particular network. The document is split into four main sections; the first section describes each of the networks that are going to be built, whilst the second section follows on from this and looks to assess what datasets within the National Infrastructure Asset Database can be used to build the networks and where data is missing. The third section introduces an interdependency matrix which details, in a qualitative manner, interdependencies that exist between components of the different networks. The third section subsequently attempts to assess how these interdependencies can be created / represented, either as a result of having explicit data defining a particular dependency / interdependency between networks, or how a particular proxy or first pass approximation can be used. Finally the fourth section introduces a series of processing steps to be performed to ensure that a topologically and spatially valid representation of each of the networks is produced.