A bathroom is a question of where the water can go, and in central Warwick the outside of the building is usually protected, which narrows the options considerably.
An external soil stack on a listed building or a conservation area frontage is not something to move on a whim, and on the narrow plots in the centre there is often only one elevation it could sensibly go on anyway. We work the drainage out before a suite is chosen rather than after, because the layout follows the waste run and not the other way round.
Floors are the second constraint and historic floors are their own case. Long spans, joists sized by eye, and three centuries of previous trades cutting notches wherever suited them. Where a waste run needs to cross joists we work to the permitted zones, and on a floor already weakened we strengthen rather than add to the damage.
Ventilation matters more in an old building than a new one, because the fabric is less tolerant of trapped moisture. An extractor discharging into a roof void puts water into historic timber, which is a slow and expensive kind of damage.
Tanking is not optional on a walk in shower. Our bathroom installations page sets out what a full refit involves.