Introduction

NEC3 and NEC4 Compared is a clause-by-clause comparison of the changes between the NEC3 Engineering and Construction Contract (ECC3) and the NEC4 Engineering and Construction Contract (ECC4). There has been considerable feedback since the launch of NEC3 and, to ensure a comprehensive review of all users' contributions, a number of working groups were set up to appraise comments and recommend actions. NEC then debated the principles of change and concluded that the time was right to produce updated versions of existing NEC3 documents together with new forms of contract to cover design build and operate contracts. These have now been published as the NEC4 suite of documents.