Will this be the only toilet in the house? Is there a separate toilet somewhere else in house?

Yes two other bathrooms in the house but will require one here as well

What height are the two windows from floor level?

1.75m from the floor height

Is this a totally new space or is there existing plumbing? If there’s existing plumbing, is a slab or do you have reasonable under floor access? Will the whole family of 5 use this bathroom if there are two others in the house?

If no need to match up with existing plumbing, this is my suggestion for layout.

Thank you so much this is very helpful!

@bigreader with young kids this is the bathroom we do the nightly bath/shower routine in. It’s existing but my husband is a plumber (so cheap labour) and it’s the top level so we have plenty of access (we will also be demoing the bottom level so will coincide the works)

With dreamers layout I would swap bath and toilet

another option with enough room for twin handbasins for crowd teeth cleaning, plenty of wall space for multiple towel racks and a giant shower stall with sliding doors could be easier for waterproofing and back to wall bath and wall hung vanity makes for easier cleaning and make sure that you take care of your plumber