This a general question regarding all standards, not just BS 7671.
Until recently I've always understood that if a project was designed/quoted prior to changes in standards/regulations that it was allowed to install to the old regs and not the new regs.
Recently I have been made aware of the advice by the NICEIC which states: "All amendments to regulations are applicable at the point in time/date that the main contract is executed/signed."
Taking that advice literally, this means that that any project quoted before the changes but due to be executed after the changes will need to comply with the new regs. Therefore the line in the sand for compliance is the date the contract is let, not the date it was designed.
A lot of the projects I work on have a long lead time between quote and order (sometimes 18-24 months) and I currently have a few due to drop that require compliance with BS 5839-6, BS 6701, and BS 7671, all of which have been amended since the original design/quotes.
Any advice or your experience of this matter greatly received.
TIA. Simon.