Buyers who only want to purchase a property if they can build an addition or put in a swimming pool should have a property survey completed as a condition of the purchase agreement. The surveyor can locate the easements (a right given to a third party to use a portion of the property for certain purposes, such as power lines or water mains) to make sure that the proposed addition will not interfere with an easement. Owners often landscape and build fences or decks over easements. This is risky because the improvements may have to be ripped out. Planting trees over utility easements is not a good idea because the roots may damage underground facilities. If this were to occur, the property owner may be liable for repairs.