I suspect I can win this......
So, I found roof bodge with batons and had to to be taken off and a new roof put on, leaking microbore central heating that had caused most of the upstairs joists to rot to the point they took the wall plates with them, so when you took the floorboards up you could push through the end of joist + wall plate and push the render off the outside of the house.
Chimney stacks rotten in roof space, so you could pick through bricks with your hands and put them into the chimney.
rotten ceiling joists hidden by plasterboard being put over old plaster and and lathe and reskimmed however plasterboard then tore small flat roof down.
sewer pipes ~ 3 inches down and cracked. Sewer Manhole cover in garden removed and left to overgrow with weeds etc to the point it was choked up with plants for 6 feet in both directions, once direction having a lot of sewage built up (months)
electrical wiring spurs created with normal kettle flex.
old plumbing pipes still in walls and with water in and broken so they slowly seeped water into walls causing interesting patterns.
lost track of small things I found.
Had a number of tradesmen walk away from the jobs, as they were too much hassle which also helped.