N.Y.C. Admin. Code § 28-112.9.2: § 28-112.9.2 Lien.

All such unpaid amounts shall constitute a lien upon the land and building upon, or in respect to which, such inspection, reinspection, examination or service was performed or permit issued when the amount thereof shall have been definitely computed as a statement of account by the department and the department shall file such statement with the department of finance for entry in the records of such department against the premises. Such lien shall have a priority over all other liens and encumbrances except for the lien of taxes and assessments. However, no lien created pursuant to section 28-112.9 shall be enforced against a subsequent purchaser in good faith or mortgagee in good faith unless the requirements of section 28-112.9.1 are satisfied.