Except as provided in section 254 of this title, even though the owner has not made an agreement giving a real estate security interest, a prime contractor, subcontractor or subsubcontractor, upon compliance with section 264 of this title has to the extent provided in this chapter a lien to secure payment of the contract price on the contracting owner's real estate which is being improved. He also has a lien on an interest in the real estate being improved of any owner, other than the contracting owner, who, in writing, has either requested that the improvement be made or agreed specifically that his interest may be bound by the lien.