Just wondered if Part P applies and to what extent,
zones apply -
Echo!-Part P applies to all electrical work within a domestic setting. Zones are restricted to rooms with baths/showers not hand basins or sinks. There are permitted safe zones that apply to cable routing.
do we need to consider having a pull cord for the light switch
or specific light fittings
Not if there is no shower or bath in the room
yep we all know Part P applies to all aspects of domestic electrical work, so in the case of moving a washing machine into a room that is currently wired with one fixed light and wall light switch and current socket layout as per post.
Is there a need for us to have alterations made to the current fix if we now subsequently add a water supply to that room.
No not unless the existing installation is unsafe? If you have carried out any alteration, this would need to comply to part p and one way of doing this is by following the recommended guidelines set down in BS7671.
Most hardwiring of buried cables and any additional socket outlets now require 30mA RCD protection, Section 7 of BS7671 will also set out the requirements of inspection and testing of existing and any new (whole or part) of the installation.
Hope this is clear, in general if you have done no alterations to the electrical installation, used common sense with regards to the potential hazard of introducing water into an area where there are electrics, then you should be fine. There is no bath/shower in that room, so those zones are not applicable! But part p will always apply!
You mention building controls inspection and sign off. So is this a new extension then, not a using up of existing space?
If so and electrical work has taken place, the inspector will require documentation from the installer with regards to the electrical work. ie minor works or electrical installation certificate, which ever applies, unless you have arrange for them to do this for you.