How small is too small for shower room with loo?

[reindeesandchristmastrees]

Looking at a 3 bed semi with downstairs bathroom and a small upstairs loo. Agents haven't measured the loo but we measured in a Heath Robinson arm span way and reckon it is approx 1.3m x 1.6m. Looking at changing the door so it either slides or opens out into the hallway and installing a very small corner shower unit in the (facing you) left hand corner of the room, slimline loo in the (facing you) right hand and a small sink on the end of the wall next to the shower (area currently hidden by the door opening into the room). Has anyone done anything similar in a very small space? We could at a push steal some space from the bedrooms next door but that increases cost considerably. How small is too small?

[Springcleanish]

We have an ensuite with a small double shower cubicle, it is about 1.2mx 1.3m, it is fine to use. We have a small bowl type sink, toilet, shower and towel rail heater.

[dancemom]

Could you make it a wet room?

[PattyMcGinty]

springcleanish - can you please let me know about your small heated towel rail?

[reindeesandchristmastrees]

Thank you so much for replies.