Decide what stays and what moves
Prepare a simple layout showing the existing and proposed bath, basin, shower and toilet positions. Moving fittings can require changes to supply pipes and waste routes. Ask the plumber to explain the practical implications before committing to a layout, including any floor or wall access needed.
Check fittings before ordering
Share product specifications as well as photographs. Taps and showers need to suit the property's water supply, while basin, bath and toilet connections must fit the proposed arrangement. If choosing brushed brass fittings, confirm the exact models and availability of replacement cartridges or other service parts.
Keep concealed parts serviceable
A clean finish should still allow future maintenance. Discuss access to isolation valves, bath wastes and concealed cistern components before boxing and tiling begin. Ask how connections will be checked before they are covered and where removable panels will be located.
Define where the plumbing job ends
A plumbing quote does not necessarily cover a complete bathroom refurbishment. Specify removal of old fittings, pipe alterations, installation, testing and waste disposal. Confirm who handles tiling, waterproofing, electrical work, flooring and decoration, and who coordinates the sequence. Ask when water will be off and when the bathroom can be used again.