N.H. Rev. Stat. Ann. § 356-B:26

No condominium shall be contracted except in accordance with the provisions of the declaration and of this chapter. Any such contraction shall be deemed to have occurred at the time of the recordation of an amendment to the declaration, executed by the declarant, containing a legal description by metes and bounds of the land withdrawn from the condominium. If portions of the withdrawable land were described pursuant to RSA 356-B:16, IV(e), then no such portion shall be so withdrawn after the conveyance of any unit on such portion. If no such portions were described, then none of the withdrawable land shall be withdrawn after the first conveyance of any unit thereon.