Conn. Gen. Stat. § 47-220: Creation of common interest community.

(a) A common interest community may be created pursuant to this chapter only by recording a declaration executed in the same manner as a deed and, in a cooperative, by conveying the real property subject to that declaration to the association. The declaration shall be recorded in every town in which any portion of the common interest community is located and shall be indexed in the grantee's index in the name of the common interest community and the association and in the grantor's index in the name of each person executing the declaration.

(b) A declaration, or an amendment to a declaration adding units, may not be recorded unless all structural components of all buildings containing or comprising any units thereby created are substantially completed in accordance with the plans, as evidenced by a recorded certificate of completion executed by a registered engineer, surveyor or architect.