Here’s what’s different:

• Office and mechanical rooms swapped (this was done because the boiler can’t vent up a chimney — too low-temperature, so the condensation from the exhaust would completely rust the thing out; on the bright side, we get to use the void upstairs because of the change)
• The previously compact tub is now a walk-in shower (custom-built, of course) and a bit of rearrangement in the bathroom, with doors relocated
• Windows added to the right-side wall (though because I can’t find an installer, they’ll have to wait until a subsequent renovation phase; there’ll eventually be a third window where the stairs currently are)

This is what we’re now going on, and the plates to handle the outer and load-bearing walls are now in place.