400mm to the rim (without the seat) is standard I think.

Fitted one last week, ideal standard washpoint, onto a Grohe frame,
built into studwork.

The Grohe frame is telescopic to make height adjustments, but on a
flat floor with the frame in the fully closed position, everything
comes out at the correct height.

Generally all very well engineered. The loo seat pivots had to be
fitted before the bowl is clamped up to the wall, and the grohe-
supplied waste coupling pipe required shortening by a few mm.

I bought a 0.82m high Grohe frame, which is better suited to having a
low shelf with the flush button facing upwards - but it's no big deal
to mount the button elsewhere, as the only connection is a thin
pneumatic hose.

I used a 12mm ply board over the frame, faced with 12mm t&v-grooved
board - very neat results indeed.

Currently fitting the other two.