i am renovating a large double fronted victorian house in london with some quite bad subsidence that has never been dealt with. I would estimate that the right hand side of the building has subsided some 15 degrees or more. There is rumour that there may be a little stream running underneath and some say a bomb went off nearby during the war - but the point is i have no idea how to deal with it or how much it will cost. Other worries are how it will effect the insurance and desirability of the property are there any particular techniques that are the best.