5.6 Building Envelope Trade-Off Option
All components of the building envelope shown on architectural drawings or installed in existing buildings shall be modeled in the proposed design. The simulation program model fenestration and opaque building envelope types and area shall be consistent with the construction documents. Any building envelope assembly that covers less than 5% of the total area of that assembly type (e.g., exterior walls) need not be separately described, provided it is similar to an assembly being modeled. If not separately described, the area of a building envelope assembly shall be added to the area of an assembly of that same type with the same orientation and thermal properties.
When the building permit being sought applies to less than the whole building, parameters relating to unmodified existing conditions or to future building components shall be identical for both the proposed envelope performance factor and the base envelope performance factor. Future building components shall meet the prescriptive requirements of Section 5.5.