Pulled out washing machine, this is what we found.

[Chuck]

Not plumbing but, in a building over 100 years old recently. And the wall runs along straight then suddenly bends by about 3 inches so as not to hit the windows.

Hmm. Are you sure that the original wall hasn't been modified by someone adding internal insulation much more recently than 100 years ago? They'd have stopped short and then curved out to avoid the window.

 

[WC1]

Is that a partition wall in a terraced property?

No, it's in a block of flats built for slum clearance in 1900's and it's all on' the cheap (and on the p!) None of the rooms are really square , floor levels are out also. I'm a bit of a geek for how buildings are built and how they work. I have got other pics of that wall on my other laptop when we were refurbishing. I think it was the setting out went wrong. It was a matter of cost to put it right so the corner was cut and it was left like that forever.

 

[WC1]

Hmm. Are you sure that the original wall hasn't been modified by someone adding internal insulation much more recently than 100 years ago? They'd have stopped short and then curved out to avoid the window.

Nope. Pics from both sides coming soon if you like when I fire up old laptop.

 

[johnduffell]

Correction, NHBC scheme once the builders finished the snagging is not a warranty for the buyers, it's purely for the mortgage company. Only the first couple of years get a warranty on basic problems that don't really affect the value, the remainder is only the structural side i.e. things that make the house drop huge value if uncorrected.
Anything that would drop the house value by less than 10% wouldn't get a look in, as the mortgage company doesn't care and buyers will keep buying regardless. But if a house is unmortgagable then obviously the builder would care about that.