Ok, Part 1 of BS7671 is Scope, object and fundamental principles. Each being allocated it’s own Chapter…
Chapter 11: Scope – Basically is what the 17th Edition Wiring Regulations apply to, eg 110.1.1 (i) to (xvi) along with the rest of page 14 and what they do not apply to, 110.2 (i) to (xii) and also covers their relationship with statutory regulations and any possible local authority licensing.
Chapter 12: Object and Effects – The objective of the wiring regulations. ie they contain the rules for the design and installation of electrical installations so as to provide for safety and proper functioning in normal use.
Chapter 13: Fundamental Principles – The largest of the 3 Chapters and gives guidance on the Fundamental or ‘basic’ Principles for…
131 Protection for Safety
132 Design
133 Selection of Electrical Equipment
134 Erection and Initial Verification of Electrical Installations
135 Periodic Inpection
Setting and laying out the criteria and agenda for the rest of the book.
Summary: Part 1 is all about what BS7671 does and does not apply to (Chapter 11) along with the purpose of the regulations (Chapter 12) and the basic principles that all electrical installations should adhere to (Chapter 13).