This topic leans a little technical, but it’s one of the most important to understand before starting a commercial build-out. Whether opening a new business or expanding into a different space, knowing how the city classifies the use of that space can make or break the project timeline.
When the planned business is different from the one that was there before, it’s often considered a change of use. That classification affects more than just paperwork. It can trigger new requirements for accessibility, safety systems, parking, and other code-driven upgrades that aren’t always obvious at first glance.
Let’s walk through what this means, when it applies, and why it matters for your budget and timeline.
What Does “Use” Mean?
In the zoning and building world, “use” refers to the type of activity happening inside the space.
There are zoning uses, which might include categories like:
- Retail sales
- Food service
- Medical/dental office
- General office
- Group classes or fitness
And there are building code occupancy classifications, such as:
- Business (B)
- Assembly (A)
- Mercantile (M)
- Factory (F)
- Residential (R)
Each use or occupancy type comes with its own set of requirements. Even if two businesses look similar to the public, the code may treat them very differently.
Examples of Common Change-of-Use Scenarios
- Office to Fitness Studio
This may trigger a switch from Business (B) to Assembly (A), requiring more exits, larger corridors, or a second accessible restroom.
- Retail Boutique to Restaurant
A jump from Mercantile (M) to Assembly or Business (B) plus Health Department involvement, and possibly new plumbing fixture counts.
- Physical Therapy to Dental Office
Still Business (B), but equipment loads and medical gas might affect structural or mechanical reviews. Even if not a formal change of use, it’s a functional change that may impact the code path.
- Warehouse to Retail
Likely a shift from Storage (S) or Factory (F) to Mercantile (M), often needing facade upgrades, accessible entries, and egress changes.
When Does it Matter?
A change of use matters most when:
- Your use type isn’t allowed under the current zoning
- It increases parking demand or requires loading
- It changes the occupancy classification in a way that impacts code
- The previous layout doesn’t meet current egress or accessibility standards for your use
- The permit reviewer flags it, requiring additional drawings or consultants
It’s not always a deal-breaker, but it does require time, planning, and sometimes reworking the scope.
How to Check Early
Before you sign the lease or start drawing, it helps to:
- Get property report for the building or parcel
- Ask the landlord what the last legal use was
- Confirm whether your business type is allowed outright, or requires approval
- Have us do an early code scan for major shifts
If there is a change of use, it doesn’t mean your project can’t move forward. It just means you’ll want to budget a bit more time for city review and potentially bring in consultants like structural, mechanical, or fire protection engineers.
Closing Thoughts
Change of use sounds technical, but it’s really just about making sure your space works safely and legally for what you’re planning to do. Understanding it early keeps you from surprises midstream, and helps your team design a space that’s built to pass review.