According to my information your landlord can not make you to pay for those changes he is making in the house you are right now. Moreover he had no right to make any changes without your permission, as you are rented this house in which you are living right now for some specific limit if there are any papers made for it. If there is written I the papers or your contract that you are responsible for any changes made in the house and you are going to pay for it then I will say you are a big fool, as your land lord can change every single thing of that house and will ask you to pay for it. So my dear fried you are not responsible for the changes. If your land lord is asking you to pay for the ramp and the sign then tell him that you have rented the house only not bought the land.
Secondly before taking a home on rent do ask you land lord that is he interested in making some changes in the house while you are living there or not if he is interested then tell him not to do so and do mention it in the contract so he will not disturb you while you were living there.
Secondly before taking a home on rent do ask you land lord that is he interested in making some changes in the house while you are living there or not if he is interested then tell him not to do so and do mention it in the contract so he will not disturb you while you were living there.