I really can't see this working without feeling cramped.

You need to mark doors and window sizes

depends on location of door and windows, choice of suitable fixtures, thickness of wall coverings and cooperation of your tradespeople but you need to decide what's most important for your lifestyle ie do you want a regular soak in a big bath or do you need a more generous handbasin with counter space and storage and, despite some toilets being quite narrow, we need to allow enough elbow and knee space around the toilet...all the sizes shown are based on readily available fixtures advertised on line and there's probably plenty of other suitable choices but keep in mind that there's probably not enough space for the necessary sloped floor for a walk in shower so i've used a shower cubicle with included door while the bathtubs, with over bath or handheld showers would probably need a glass screen for stand up showers ..some ideas to consider but you should measure out the walking distances between fixtures to see how much standing and drying space is available

Who’s going to use the space?

It will be a holiday let

My favourite way to combine a bath and shower, and would be perfect for your holiday let

Looks lovely Siriuskey, but awkward to bathe little kids and requires lots of water to fill to a reasonable depth as well as great tanking.

A smaller 1200x700 bath might fit, but we need room orientation, windows, door location. I have a 900 bth in my holiday home, but it is old and not sure where to get one now.

Kate having had little kids and grandies and used this setup, it works brilliantly, you don't fill the bath just do the same as you would for your average bath tub, you sit on the edge (make sure the ledge is wide enough to sit on as per a normal tub), it's also very safe and non slip

If it’s a holiday let, I’d forgo the bath.