I have just been to see a listed property from the outside everything looks pretty normal. the property is split into two x two bedroom flats.When we looked at the flat upstairs the stair to the attic room was all leaning toowards the middle of the stairwell running off at least 75 mm accross the step. At the front of the house the bathroom floor also was also falling towards the middle of the flat. when we went down to the bottom flat which is the first floor and then the basement. there were acrow jacks under the ceiling which i presume was supporting the floor above from falling any further and then the another set of acrow jacks in the basement which is a concrete floor which i presume that this is all transfering the weight into the basement floor. I m not a builder but this looks a serious problem to solve needing steel and a new floor and staircase anybody out there who has solved this type of problem who can advise how much this type of work cost and would i need to involve a structural engineer.