Other than the lengths & height of outlets in special locations such as Marinas & Caravan parks, zones in bath/shower rooms ect... (Part 7 page 164 onward ), AFAIK there are NO wiring regulations stating the physical positions, heights, widths, distances of ANYTHING!
other than the general guidance of:
Accessibility 132.12 page 18
External Influences 512.2 page 90
Presence of water 522.3 page 99
Of course manufactures instructions need to be followed 134.1.1 page 19
So you will use you own skill & judgement to assess appropriate locations.
However there are the instances where Building regulations need to be applied...
i.e. socket switch heights for accessibility Part M compliance.
Electricians guide to the building regulations recommends 300mm from appliances, cookers, hobs, sinks.