Wis. Stat. § 703.26

(1)   Declarant may reserve right to expand. A declarant may reserve the right to expand a condominium by subjecting additional property to the condominium declaration in such a manner that as each additional property is subjected to the condominium declaration, the percentage of undivided interests in the common elements of the preceding and new property shall be reallocated between the unit owners on the basis of the aggregate undivided interest in the common elements appertaining to the property. (2)   Conditions to which reservation subject. A reservation of the right to expand a condominium is subject to all of the following conditions: (a) The declaration establishing the condominium describes each parcel of property that may be added to the condominium. (b) 703.26(2)(b)1. 1. The declaration establishing the condominium shows all of the following: 703.26(2)(b)1.a. a. The maximum number of units that may be added to the condominium. 703.26(2)(b)1.b. b. The percentage interests in the common elements, the liabilities for common expenses, and the rights to common surpluses appurtenant to each unit following the addition of property to the condominium. 703.26(2)(b)1.c. c. The number of votes appurtenant to each unit following the addition of property to the condominium, if added. 703.26(2)(b)2. 2. The information under subd. 1. b. and c. may be shown by reference to a formula or other appropriate method of determining them following each expansion of the condominium. (c) The plat for the original condominium includes the outlines of the land and, in general terms, the location of the buildings and common elements of new property that may be added to the condominium. (d) The right to expand the condominium is reserved in the declaration for a period not exceeding 10 years from the date of recording of the declaration. (3)   Recording amendments and addenda. (a) If the conditions of sub. (2) are met, property may be added to a condominium if the declarant records all of the following: 703.26(3)(a)1. 1. An amendment that shows the new percentage interests of the unit owners and the votes that each unit owner may cast in the condominium as expanded. 703.26(3)(a)2. 2. An addendum that includes the detail and information concerning the new property that is required for a plat under s.