The owner shall record at the Middlesex South District Registry of Deeds an historic preservation restriction in the form approved by the Zoning Board of Appeals, and approved and endorsed by the Massachusetts Historical Commission in accordance with Chapter 184, Section 32, of the Massachusetts General Laws, which shall at a minimum provide for conditions under which alterations, additions or modifications may be made, and in the event of damage to the historic structure such that the historic structure cannot be repaired, the owner may rebuild on the lot, provided that the new dwelling does not contain more than the same interior floor area as the historic structure and meets one of the following requirements: (i) the new dwelling is placed in the existing footprint; or (ii) the new dwelling is built in conformity with the zoning side, front and rear setbacks in effect at the time of rebuilding. Any mortgagee shall subordinate its mortgage to this restriction.