In case there were a similar situation you knew or saw,
The rumpus was garage before converted in 70s, conrete slab, brick veneer wall. Noted a back corner sinking several years ago when moved in, and a big tree was removed around that time with stumps grindered.
That corner side seems sinking each year and now the front corner in the same side now have 1 cm gap. Recently tried to get into craw space and noted some water sitting same side, where then identified a downsprout blocked by leaves below ground. The position is about 2 to 3 meters to the sunken corner as mentioned above. Got a plumber to clean out the storm drains and replaced broken part near front and most likely by tree root. It all happens in the same side!
I am thinking what would be reasonable or good to level indoor slab, and Who to engage i.e. a civil engineer first, and timing , let moisture gone say after summer to repair? Any experience or recommendation ? Thanks