“Real property” or “real estate” means an identified parcel or tract of land with improvements (i.e., any buildings or other structures, including fences, driveways) constructed or installed on the land in a permanent manner and includes easements, rights of way, undivided and future interests and similar rights in a tract of land. Unless or until severed, a lien on real estate includes mineral rights, timber right, growing crops, water rights and similar interests. Real property includes not only the ordinary building materials (brick, mortar, doors, windows, etc.) that were used to construct a building, but also goods that were installed in and have become an integral part of the building, such as light fixtures, elevators and heating and air conditioning equipment.