Requirement G3 – Hot Water Supply and Systems
What are the controls on the hot water supply and hot water systems?
With regard to supply, the provision requires that heated wholesome water (or softened wholesome water) is provided to any washbasin or bidet provided in or adjacent to a room containing a sanitary convenience, to any washbasin, bidet, bath or shower in a bathroom and to any sink provided in any area where food is prepared.
Doesn't say there must be a basin.
Requirement G4 – Sanitary Conveniences and Washing Facilities
What is required by G4?
This provision is similar to that contained in G1 of the previous edition of Approved Document G, but there is no longer any requirement for cleanability in the current edition. It sets out that adequate and suitable sanitary conveniences (WCs and urinals) must be provided in toilets or bathrooms and that adequate hand washing facilities must be provided in or adjacent to rooms containing sanitary conveniences. Any room containing a sanitary convenience, bidet or facility for washing hands associated with a sanitary convenience must be separate from a kitchen or area where food is prepared.
In or adjacent to....
Requirement G5 – Bathrooms
What bathroom provision is required by G5?
This requires that in dwellings and in buildings containing one or more rooms for residential purposes a bathroom must be provided containing a wash basin and either a fixed bath or shower.
But nothing about loos and basins.
As it is not a commercial building/letting or in multiple occupancy I don't think there is a requirement
www.planningportal.gov.uk/permission/commonprojects/kitchensbathrooms/#ImpactonaccessibilityofgroundfloorWCs
No mention there either