Except as hereinafter provided, damage to or destruction of the building or of one or more of several buildings which comprise the property shall be promptly repaired and restored by the council using the proceeds of insurance held by the council, if any, for that purpose, and the unit owners directly affected thereby shall be liable for assessment for any deficiency in proportion to their respective undivided ownership of the common elements: Provided, however, That if there is substantially total destruction of the building or of one or more of several buildings which comprise the property, or if seventy-five percent of the unit owners directly affected thereby duly resolve not to proceed with repair or restoration, then, and in that event, the salvage value of the property or of the substantially destroyed building or buildings shall be subject to partition at the suit of any unit owner directly affected thereby, in which event the net proceeds of sale, together with the net proceeds of insurance policies held by the council, if any, shall be considered as one fund and shall be divided among all the unit owners directly affected thereby in proportion to their respective undivided ownership of the common elements, after discharging, out of the respective shares of unit owners directly affected thereby, to the extent sufficient for the purpose, all liens against the units of such unit owners.