Required minimum lot size. The required minimum lot sizes for all principle uses permitted in the Open Space (OS) District shall be established by the Town Planning Board during the site plan review and approval process or the special use permit approval process. The required minimum lot size shall be based on the amount of land area necessary to adequately accommodate the proposed principle use, as well as all parking, loading, landscaping, open space, setback and access areas and fire lanes for such use. The required minimum lot size shall also be based on the relative intensity of the proposed land use, the requirements regarding the maximum percentage of lot occupancy contained in this section, the need to protect the proposed use from surrounding land use development patterns and the need to protect sensitive environmental areas, significant historic or archaeological areas or scenic views or vistas.