Interpretation #: CEB-2022-07-2014 IBC-1203.1

Building or Fire Safety Law Interpreted

675 IAC 13-2.6 2014 Indiana Building Code, Section 1203.1 (Ventilation) General. Buildings shall be provided with natural ventilation in accordance with Section 1203.4, or mechanical ventilation in accordance with Section 403 of the International Mechanical Code.

Issue

Whether the ventilation requirements of Section 1203.1 of the 2014 Indiana Building Code (IBC) apply to shell spaces intended for completion and occupancy at a future date.

Interpretation of the State Building Commissioner

No, ventilation requirements of Section 1203.1 of the 2014 IBC do not apply to shell spaces intended for completion and occupancy at a future date.

Rationale

Constructing shell buildings, or buildings only partly completed and occupied, with the remaining spaces reserved for speculative occupancy, is common practice in our economy. While some code requirements such as structural design loads are obviously applicable to the building at large, others are tied to occupancy, whether through the nature of the space's use, the number of occupants the space will contain, or even the fact that the space is occupied at all. In those spaces that are left unfinished and intentionally unoccupiable, these latter requirements cannot be applied. The ventilation regulation in IBC 1203.1 is such a requirement.

The code contains no prohibition on leaving unfinished those portions of a building that are initially unoccupied, provided the rest of the building, including the portion that is initially occupied, meets all its own applicable code requirements. The requirements and means for mechanical ventilation are intended to be applied to occupied spaces. If the spaces are not occupied, there is no overarching reason to bring them to levels of comfort or safety required for humans. We have no reason to believe this is contrary or burdensome to the occupancy permit process of the authority having jurisdiction, since this scenario appears most often in multi-tenant structures, and in such structures, occupancy permits are typically issued for individual tenant spaces and not a single permit for the entire building.

However, in deliberately leaving a portion of a structure unoccupiable, the owner takes on the responsibility to ensure the portion of the structure that is occupied meets all code requirements that are applicable to that part of the building, and to ensure the building as a unit is compliant with all regulations applicable to the structure at large. Since the local official has expressed concerns about the environmental consequences of leaving an entirely unconditioned interior space, it must be noted that energy performance is among the requirements with which the entire structure is expected to comply upon its initial occupancy. If a portion of the building is to be left unoccupiable and unconditioned for an indeterminate period after the initially complete portion is finished and occupied, those unconditioned spaces must be considered in the energy design and performance of the building. In such cases, an energy model based on a fully occupiable building is irrelevant, and will remain so until the building is (or is imminently) fully occupiable. Until that point in time, the building must be demonstrated to meet energy performance requirements as it is initially constructed. Failure to do so would be to occupy a noncompliant building.