Should I rough in a future elevator shaft when building an Arizona custom home?

The cheap version is simple: stack two closets, one above the other, and frame the floors and structure so the opening is ready for a future elevator shaft. That costs a few thousand dollars now. Retrofitting an elevator into a finished house can cost many thousands more, because the crew has to cut through floors, reroute framing, and work around a slab that was never meant to hold a pit.

The decision comes down to two numbers. Roughing in a shaft is cheap insurance taken during a build that is already open to the framing. A retrofit is expensive surgery on a finished home. You do not have to install the elevator now. You just have to leave the door open for it. This page covers the stacked-closet method, what rough-in actually involves, and the cost gap. For whether an elevator itself is worth it, see our guide on home elevators in an Arizona custom home.

The stacked-closet method

The cleanest way to rough in a future elevator is the stacked-closet method, where you place a closet on the first floor directly below a matching closet on the second floor. Each closet is sized to fit a residential elevator car plus its shaft walls, usually a footprint close to a 5-by-5-foot space. Until the elevator goes in, the two closets are usable storage on each level. When you are ready, the floor between them opens up and the car drops in.

The reason this works is that the hard part of an elevator is not the machine, it is the hoistway, the vertical shaft the car rides in. Building that shaft into the home from the start means the framing, the floor openings, and the wall locations are already correct. You are not stealing space from finished rooms or rebuilding a corner of the house later. You are using closets you would have built anyway.

Plan the closets with your builder and an elevator manufacturer during the design phase, so the dimensions match a real car you might buy. A car that needs a 5-by-5 shaft will not fit a stack of 3-by-4 closets. Getting the size right on paper costs nothing. This is the same design-first discipline that wins on every part of a custom home, covered in our overview of the custom home design phase.

What roughing in a shaft actually involves

Roughing in an elevator shaft means preparing the structure, the pit, the power, and the openings during construction, without installing the car. A good rough-in usually covers four things, and each is far easier to do before drywall closes the walls.

• The shaft and floor openings. The framing is laid out so the two stacked closets can be opened into a single vertical chase. The floor structure between them is built to be removed cleanly later, not laced with beams that would have to be cut.
• The pit. Most residential elevators need a pit, a shallow recess below the lowest floor where the car rests at the bottom of travel, often about 8 to 14 inches deep. In Arizona this matters, because most Valley homes sit on a post-tension slab with cables that cannot be cut after the pour. Forming the pit, or a low-pit alternative, during the foundation stage is the only clean way to do it. Our guide on why Arizona uses post-tension slabs explains the foundation you are working around.
• The power and communication. A dedicated electrical circuit and a path for an emergency phone line are run to the shaft location and capped, ready to connect.
• Overhead clearance. The ceiling structure above the top floor leaves room for the car to overrun safely, and a small machine space if the design needs one.

You do not buy or hang the car, the rails, or the doors during rough-in. Those come later when you commission the actual elevator. The rough-in just makes sure that day is a clean install, not a demolition project.

What the code requires

A residential elevator in Arizona must meet ASME A17.1 Section 5.3, the national safety code for private residence elevators, which the International Residential Code points to and most Arizona cities enforce through their adopted building code. The IRC addresses elevators and platform lifts in Section R321, which directs residential elevators to the ASME A17.1/A17.3 standard. States that license elevators, like Texas, require any new private-residence elevator to "conform to the ASME A17.1" standard and be inspected after install. Arizona cities inspect the work through the local building department, and a licensed elevator installer pulls the permit.

Section 5.3 controls the shaft and car tightly. The inside clear area of a residential elevator cannot exceed a set size, which keeps a private elevator from becoming a freight lift, and the hoistway must be enclosed and fire-rated for its full height. The car needs overhead clearance and a pit at the bottom. None of this changes whether you rough in now or retrofit later, but roughing in early makes meeting the code far simpler, because the fire-rated shaft and the pit are built into the structure instead of carved into a finished house.

Ceiling height plays in too. The IRC sets a minimum ceiling height of 7 feet for habitable rooms under Section R305, and an elevator shaft and machine space have their own clearance needs stacked on top. Planning the vertical space during design keeps the elevator, the ceilings, and the structure from fighting each other. Confirm the exact code edition your city enforces with your builder, since adopted codes vary by jurisdiction.

Rough-in cost versus retrofit cost

Roughing in a future shaft during construction typically adds only a few thousand dollars, while retrofitting an elevator into a finished home can add many thousands more on top of the elevator itself. The gap is the whole reason to plan ahead. During a build, framing two stacked closets, forming the pit, and running a capped circuit is a small change order on a project already open to the structure. The crew is on site, the walls are open, and the slab is being poured.

A retrofit is a different animal. Cutting an elevator into a finished house means opening floors and ceilings, rerouting framing, and finding a way to add a pit to a slab that was never designed for one. On a post-tension foundation, that pit problem alone can be a serious engineering challenge. Add the drywall, flooring, and finish repair after the structural work, and the disruption climbs fast. A full residential elevator usually runs about $30,000 to $75,000 installed in 2026, and a retrofit stacks demolition and repair costs on top of that.

The honest takeaway is that rough-in is cheap optionality and retrofit is expensive regret. If you are on the fence, the rough-in is the low-risk move: a small cost now, two usable closets in the meantime, and a clean install whenever you decide you want the elevator. Confirm current pricing with a licensed builder and elevator installer on your real plan, since equipment and labor costs move and adopted codes change over time. Once the shaft is roughed in, turning it into a working elevator is a planned upgrade instead of a teardown.

Where Jematell Homes comes in

Desert-smart design and systems are standard on every home we build. If you are planning a custom home in Scottsdale, Rio Verde, or the greater Phoenix metro, we are happy to walk through your project.

Sources

• 2021 International Residential Code R321 (Elevators and platform lifts) (ICC Digital Codes)
• Texas Department of Licensing and Regulation: Elevator Safety and Licensing FAQ (ASME A17.1 adoption)
• 2021 International Residential Code R305 (Ceiling height) (ICC Digital Codes)