When a business owner considers moving into an existing space, they must determine whether the code allows the proposed use. If the new business is sufficiently different from the prior tenant, the proposed renovation may result in what codes refer to as a Change of Occupancy. Understanding this condition allows business owners to make good decisions when relocating.
What is a Change of Occupancy?
A Change of Occupancy occurs when the use of a space changes, moving it from one occupancy classification to another. Building code occupancy classifications define the primary purpose of a space or structure. Some buildings contain multiple occupancy types, and the code regulates how these function together or separately.
For example, a professional office typically falls within Group B Business occupancy, while a restaurant, theater, or event space may fall within Group A Assembly occupancy. If an existing office converts into a large restaurant or event venue, the classification changes and the project becomes a Change of Occupancy.
Do I need an architect?
Yes. Oregon law requires a licensed architect to prepare stamped permit documents for a Change of Occupancy or Use.
Why does a Change of Occupancy require a permit?
A Change of Occupancy can introduce different safety requirements under the building code. Each occupancy group carries different expectations for how many people may occupy a space, how occupants exit the building, and how the building must perform during a fire or other emergency.
Assembly spaces such as restaurants or event venues often allow more occupants than a typical office. These differences can affect requirements for exits, fire-rated construction, accessibility, and in some cases, the structural capacity of the building. Depending on whether the building is sprinklered, a Change of Occupancy may also require new fire separations between tenants with different occupancy classifications.
The zoning code is also concerned with changes in the use of a tenant space for similar reasons. Different businesses attract different numbers and types of visitors and can place different demands on a site. The zoning code provides direction for how a site is developed at the neighborhood scale, including use, landscaping, vehicle access, and other improvements. These requirements vary depending on the proposed business use.
Because of these differences, the building department reviews a proposed Change of Occupancy to determine whether the new use is allowed and whether the existing site and building can support it.
The City of Portland provides guidance on Change of Use or Occupancy requirements on its website, along with a detailed informational brochure.
What is a common Change of Occupancy scenario?
Converting a warehouse into an event venue is a common example. A warehouse used for storage is typically a Group S occupancy, while an event venue is classified as Group A Assembly. In some cases, this change can increase the number of occupants by 30 to 100 times. That shift has significant implications for life safety and building performance, often requiring upgrades to exiting, fire protection systems, and sometimes structural capacity to support the new use.
What if my Assembly space is small?
There is a special carve-out for assembly spaces with fewer than 50 people: they can remain a Group B classification.
This means that converting an office into a small café, meeting room, or community space may not trigger a Change of Occupancy. The details matter, so it’s important to review these specifics early.
Will a Change of Occupancy trigger seismic upgrades?
Sometimes, depending on the building. In some cases, a Change of Occupancy prompts an evaluation of the existing structure for seismic resistance. If the building does not meet current requirements, it may require upgrades—and these can be significant, especially for a small tenant improvement. For larger projects, particularly when taking over an entire building, the scope may justify the investment.
A future post will take a closer look at seismic upgrade requirements and what they can mean for a project.
What if I have both a Change of Use and Change of Occupancy?
A project may involve both a Change of Use and a Change of Occupancy. When this occurs, the building code treats the project as a Change of Occupancy.
What does this mean for a tenant improvement project?
A Change of Occupancy can significantly affect the scope of a tenant improvement project. Evaluation by an architect or engineer will provide the clearest understanding of the specific requirements.
Identifying whether a proposed project involves a Change of Occupancy early in the process can help identify potential requirements before design and permitting begin. If you’re planning a tenant improvement project, we can help evaluate the proposed use and guide the project through design and permitting. Contact us to start the conversation.