Tenant Improvement Plumbing in Phoenix

A TI covers whatever the new use requires, and the plumbing scope follows the business. It usually includes demolishing abandoned fixtures and capping lines, rough-in of new drains, vents and water lines, setting restroom fixtures, adding floor sinks or a mop sink, a water heater, backflow protection where the use calls for it, and sometimes gas piping. The existing FAQ on what plumbing a commercial tenant improvement involves lists the common items by business type. A restaurant adds interceptors and kitchen drains, a clinic adds sinks at every exam room, and a retail shell may add only restrooms and a service sink.

Two jobs in a TI are large enough to have their own pages: restroom remodel plumbing and mop sink and floor sink installation.

The number comes from the occupancy classification and the occupant load, not from what the previous tenant had. Table 403.1 in the 2024 IPC sets minimums for water closets, lavatories, drinking fountains and service sinks by use, and the occupant load comes from the building code. Phoenix amends Section 403.2 so that separate men's and women's facilities are not required in a tenant space of 15 occupants or fewer, in mercantile or business occupancies of 50 or fewer, or where single-user rooms are used. Anything not in the table is decided by the code official. This is why the fixture analysis goes into the plan set before pricing: a change of use from office to restaurant can change the count on its own.

Plans go to the building department that covers the address, and the plumbing plan has to be specific. Phoenix's checklist asks for the floor plan, a minimum plumbing fixture analysis, fixture schedules, drain, waste and vent sizing isometrics, water and meter sizing calculations, backflow devices and expansion tanks. Mesa has a voluntary permit-by-inspection program for small Group B, M and S tenant improvements of 10,000 square feet or less, where inspectors review and issue the permit. Scottsdale sets 180-day limits on stale applications and temporary certificates of occupancy, so a schedule that slips can restart paperwork. Other cities differ again, so ask for the city's checklist before you price. Our Phoenix tenant improvement permit and Mesa permit by inspection pages go into more detail.

Plumbing goes in twice, before the walls close and after the finishes. Rough-in comes first: any under-slab trenching and drains are set and inspected before the slab is patched, and water, drain and vent piping in walls and ceilings is inspected before it is covered. Phoenix's amended code says concealed service equipment may not be covered until it is inspected and approved. Finish plumbing follows, setting fixtures, trim and floor drains, with a final inspection before the space opens. HQ works with the general contractor on timing so the slab, framing and ceiling are not closed ahead of the inspector. Ask for the rough-in date in writing, because a missed inspection can mean opening finished work. Commercial plumbing permit revisions are worth reading if the layout changes after approval.

Often they do. Under the 2010 ADA Standards, an altered element or space must comply, and an alteration affecting a primary function area must also make the path of travel to it, including the restrooms, accessible to the maximum extent feasible, unless the cost is disproportionate. The advisory text cites 20 percent of the alteration cost as the disproportionality benchmark. That is why a small TI can still include a restroom upgrade. See alteration and the ADA path of travel for how this works in practice.

If the tenant is taking a space for the same use, with the same fixtures in the same places, you may only need a repair, a fixture swap or a permit-exempt change. Minor work may not need plans at all. Check whether the job is repair or new work before hiring for a build-out. If an existing floor sink or interceptor is shared with neighbors, a repair may be a landlord item. And if the real need is a new restroom, a restroom remodel is the better fit.

Send the plan set, the suite address, the permit status and your target open date. HQ gives free estimates, upfront pricing before work starts, and is licensed and insured. For related needs, see our commercial plumbing page, restaurant plumbing, property management plumbing and gas line service.