When tiling the floor in 300mm tiles and the walls in 150mm tiles, would
you try to align the wall and floor grout lines, it looks smart that way
in SketchUp, but given the non-square nature of most corners, is that
asking for trouble in reality? Would you do the opposite and have the
floor tile grout lines centred on the wall tiles, so if it "walks" a
little as you go round the room it's not so noticeable?

I seem to remember Andrew Gabriel mentioning "poor man's" UFH, the floor
area excluding the bath is only 6'x4'. Looking for enough to take the
chill off the tiles, rather go for the cat on a hot tin roof effect or
expect too much actual heating of the room. I could easily run a couple
of zig-zags of 15mm pipe in-series with the bathroom radiator, or if
microbore would be good enough it would probably less hassle to thread
that in ... thoughts?

Any recommendations for humidistat fans (wall or ceiling mount equally
possible) quiet is good, particularly so the shutters don't click and
clack in the wind all night long.

I think the current Mira Excel mixer shower is old enough that it
doesn't owe me anything, so probably best to replace rather than dig it
out of the wall and re-fit. Are their BIV ones still the same sort of
quality as ~20 years ago? All their shower handsets seem to be chrome
plated plastic now, which looks tackier than plain white to me, who else
to look at?