We have recently completed an electrical estimate for an office block toilet refurbishment project where shower circuits were being added and the lighting was being altered.

The drawing called for 50A SP MCB and SWA supply, but didn’t mention that an RCBO should be fitted.

BS 7671 :Reg 701.411.3.3 requires CIRCUITS FOR OR PASSING THROUGH that areas containing baths or shower should be protected by an RCD.

The consultant had missed this new requirement of Amendment 3 which came into effect from

1st July 2015 – From this date it is a requirement that all electrical installations designed and periodically inspected comply with the updated regulations.

Given there is 7 circuits and 7no RCBO required this oversight could cost the contractor £250 to £450 on their electrical estimate subject to the short circuit rating required.

Electrical estimators are well aware  the consultant would probably rely on their reference to BS7671 and all amendments compliance