This means you are responsible for all the costs that lead to merely establishing the claim. Only then can the cost of underpinning the foundations be considered. And not only that, you must be sure that the strengthening work is carried out properly, and that the signs of the subsidence are not just covered up in the hope that no one will notice. It happens! Later, you might want to sell your house, and a prospective buyer’s surveyor discovers the problem has actually worsened.