Interesting to see the pictures - definitely has character!

Posted By: PortugalProjectThe French video is excellent and I intend to incorporate a version of it when the roof is removed, though not wishing to Infringe on my limited internal space any further I’m still problem hunting how to do a ground floor level support.

Possibly run a concrete ring beam below the new floor, with vertical columns connecting to the 1st floor and roof, as per video 1.

Posted By: Ed DaviesI sent a structural engineer some photos from which he was pretty sure of what was going on but neither he nor I would have been happy to go with that until he'd come and had a look himself.

I can see why some would refuse, but pre-Covid GPs wouldn't have been comfortable seeing their patients remotely, yet in 70-80% of cases that's now happening.

Posted By: djh
Double check legalities since we've left the EU. I can imagine you can legally use any EU engineer, but UK might be stretching it.

UK engineers are OK until the end of this year under the 'transition', probably not in 2021.

Posted By: Peter_in_HungaryBuilders are not very good at following plans, they use the plans to get the footprint dimensions and then just build the way they always have.

Yes, for small builders, that seems a universal rule. You'll need to explain what and why and keep a constant watch.

Posted By: JontiI would be very, very careful when starting to remove structural parts of this building.

Yes, especially when it has evidently moved - do get a structural engineer involved as per my suggestion above.

Under said concrete floor (3cm max) I found.....

Cleaning the old render from the internal side of the 2000yr old wall I created....

Seems quite a large area of missing dirt that I guess must be water erosion, that could go some way to explaining why only this area of the house walls are leaning.
There was always a damp smell in the lower part of the house but on checking the dirt I was surprised to find it very moist, not quite wet but well beyond damp!
Certainly reinforces my idea that some foundation work would be advisable.

As always any advice, stories or experiences are welcome

There may have been some flow of water beneath the floor - I wonder if you can trace a channel of voids below the floor, which might support the idea. Another possibility is that the voids may have resulted from ground / wall movement - soil can undergo liquefaction during earthquakes. It's quite likely that the concrete has contributed to moisture buildup.

Posted By: PortugalProjectI’m rethinking the leca and underfloor heating idea

The biggest determinant of viability would probably be if the foundations don't go down much deeper than the floor. You'd need a couple of small gingerly dug trial pits to determine that, and I'd suggest that structural engineer again before embarking on that...

As for the quarry / clay tiles, I wonder if enough can be salvaged to be reused in a part of the building - as they would be vapour permeable they could be relaid OK on a limecrete slab. Maybe you could obtain more from elsewhere, or find new ones that match reasonably well.

Posted By: Pile-o-StoneI saw someone retrofit foundations to an old building (a barn conversion) where they dug out a small section under the wall and poured reinforced concrete, then just moved along the wall until the whole building was done.

Underpinning can also be done by grout injection in some circumstances. Though I wouldn't go to the expense of either just to lower an adequate floor level, and not without advice from a structural engineer. Done incorrectly it can make the situation worse, and potentially much worse.

Posted By: PortugalProjectCleaning the old render from the internal side of the 2000yr old wall I created....

The photo following this statement looks more like the floor. Is that really the wall?

Posted By: Pile-o-StoneI saw someone retrofit foundations to an old building (a barn conversion) where they dug out a small section under the wall and poured reinforced concrete, then just moved along the wall until the whole building was done.

As quoted above this is called underpinning and is quite a standard procedure but with the type of walls you have

Posted By: Pile-o-StoneNot for the faint hearted

The use of a structural engineer is often required but often only for the regulations because the authorities want to see the calculations to justify the plans. The UK has got around this issue in some circumstances by having 'deemed to comply' which means that certain materials in given circumstances do not need to be justified by calculation. A good builder e.g. will be able to put in foundations and build a wall without an SE because they know what they are doing. In the same way a roofer will be able to put up a (standard) roof without an SE because it is their job. An architect will be able to draw plans for what ever goes for standard in their area (and they usually have tame SEs available)

You need to understand what you have. Dig a couple of (narrow) holes next to the outside walls to see what if any foundations you have. This will govern what you can do with the floors. If you have the ceiling height you could build up on the existing.

If you are going to replace the roof I would strongly recommend putting a ring beam on the wall. If it is a normal procedure where you are (it is here) then a builder should know how to do it, if it is not usual practice then it will need designing and the builder persuaded to follow the plan.

Posted By: PortugalProjectMy current plan is to remove everything except two walls so bearing in mind that means a new roof, all floors, all electrics, all plumbing, all internal walls, etc so any knock on effects will hopefully be covered.

Hmm - and given that foundations my be in question -- Do you have more than a building plot?
It may actually work out cheaper to start again saving what architectural features e.g.roof tiles that is either prudent or what the conservation officers wants. New build can be made to look old (especially if rendering is used) and insulation is much easier to fit rather than retro-fit.

Peter you are quite right regards the photo... my mistake in attaching the wrong one!

Ring beam I’ve already decided 100% on fitting, the test small holes/trenches I will do as soon as the engineer has visited.

You are also quite right about not being much more than a building site and argument to just do a new build... HOWEVER, due to the historical UNESCO aspect it’s an absolute no no (though it was suggested that if I made the builder a decent offer then the walls may “FALL” down accidentally but I really don’t want to risk that route).

I hope everyone is keeping well and thanks as always for any and all input