For the purposes of this article, all materials furnished, all work done, and all services provided by any one person, firm or corporation, upon any one building or the improvements appurtenant thereto, or upon the real property whereon the same stands, or to which it may have been removed, shall be deemed and considered one contract, whether or not all of such material was bought at one time, or under one general agreement or otherwise, and whether or not all of such work, labor or services provided, was contracted for at one time or otherwise.