The tub was on the right, next to the toilet, the sink across the door, on the left of the window. Left of the door: a huge 150l (not quite 40 gallon) wall mounted electric water heater.
The medicine cabinet with two 25W bulbs was the only light, making the room even creepier at night. In fact the only nice feature is the old (I don't write original, since in this house it's absolutely impossible to tell what might be original, and the ceiling probably isn't as the beams are sawn rather than hewn).
We pretty soon decided to make the bathroom a bit more compact by rotating the tub 90 degrees and closing off a water closet around the current toilet location. That gives us an almost square bathroom and resolves any family quarrels (I mean who likes to be in the tub while someone is sitting on the toilet and vice versa? We're an open family raised in hippie spirit, but that's too much!). A standard tub barely fits the old bathroom, but we'd like a clawfoot or larger modern tub, both of which wouldn't (most clawfoots here are about 5cm longer than modern standard tubs). As soon as we discovered that the wall sits on top of the screed (which has a 5cm step in the hallway making a lovely tripping hazard and is seriously damp) it was clear that it had to go. We expected hollow block bricks, but alas, the wall was built of concrete block with cement mortar. As you can see the mortar was even stronger than the block. Took us two days with a sledge hammer to get rid of it.
"ThereIfixedit.com" as my brother called it... as we still needed water for the construction, we left the galvanised plumbing in place, the tub feed hanging in mid air. 
Around Christmas we started the rebuild. First we laid a brick foundation, then tar paper. We didn't get started on the actual walls though because we ran out of time. This week we could finally start laying the aerated concrete block. The first glory shot shows you the approximate layout minus the doors (the blocks just sit there to weight down the tar paper).
Once we started laying the block, we needed to get the door frames in place as the wall is built around them (were this a brick wall, the frames would be installed after the wall is done, but with those blocks it's easier to put up the frame first). The frames we built after Christmas are solid pine 2x5 to match our salvaged panel doors. 
Of course they won't stand on their own, so we needed to get creative again. 
As soon as this was done, the walls realy started going up. Since the block is lightweight and very smooth things should go pretty fast (one block is 60x25x10cm, 24x10x4" and they're mortared using thinset applied with a notched trowel) but since we actually have to build three walls with two door frames the cutting slowed down things considerably. In spite of the name "concrete" the blocks can be cut using a regular wood saw (it goes dull though, so we used an old cheap one that came with the house). With two work days we got about half done as most of the time I was working alone or with very little help. With 1 guy cutting full time and 2 mortaring things would have gone considerably faster. In the bathroom, looking out into the new hallway: 
A second plumber gave us a quote for the central heat and plumbing which came in at only half of the first quote. He wants to sell us a Baxi boiler though, and online reviews were seriously bad. Besides, Vaillant gives you a 5 year warranty against scaling if you live in a hard water area, and that's exactly what we need! However, even if a Vaillant boiler increases the bill by about €1000 we'Re still much cheaper than with the first quote. Once the hot and cold water lines and drains are done it's time for subfloors and plaster!
As usual, there are still a few things left before that though, at least the plaster part. The wiring isn't anywhere near done yet and more than half of the door frames are still missing (at least 3 need to be built from scratch and installed and one has to be modified and installed). Once this is done, plaster can go up. Once the plastering is done, the heating pipes and radiators can be installed, followed by the floors. That leaves the 10 dozen other jobs like painting, tile, etc.
