i did this with ip65 downlights in a home that did not have any rcd's "old re-wireables " i did a post a while back on here. tbh i hope one day rcbo's become really cheap so we could just have every circuit on its own. saves half or all circuits going off at one time XD
reading threw a document from a site it says
Zone 0 is inside the bath or shower itself. Any fitting used in this zone must be low voltage, (max 12v) and be rated at least IP67 which is total immersion proof.
Zone 1 is the area above the bath to a height of 2.25m from the floor. In this zone a
minimum rating of IP44 is required. If the fitting is 240v a 30ma residual current device
(RCD) must also be used to protect the circuit in this zone.
Zone 2 is an area stretching 0.6m outside the perimeter of the bath and to a height of
2.25m from the floor. In this zone an IP rating of at least IP44 is required. In addition it
is good practice to consider the area around a wash basin, within a 60cm radius of any
tap to be
considered as zone 2.
Zone 3 is anywhere outside zones 0,1 and 2 (subject to specific limits) and where no
water jet is likely to be used. No IP rating is required. In addition to the above, if there is
a likelihood of water jets being used for cleaning purpose in zones 1,2 and 3 a fitting
rated a minimum IP65 must be used