How should I budget a curbless accessible route during new construction?

For that 45-foot route and 18-inch rise, I’d separate the budget into three buckets rather than one accessibility package:

- **Sitework:** grading, driveway approach, retaining walls, drainage, and the exterior ramp or reworked slope.
- **Structural work:** foundation elevations, slab or framing changes, entry landing, door thresholds, and any required beams or headers.
- **Finish-level accessibility:** wider doors, flooring transitions, hardware, blocking, and electrical rough-ins.

Ask the designer to show alternates for deferring each bucket, including both the future cost and the disruption. Sitework and structural changes are usually the risky items to postpone, since they can mean excavation, concrete removal, or reframing. Blocking and conduit are comparatively cheap while walls and ceilings are open.

For the 18-inch change, is the designer comparing a regraded approach against a ramp or a raised entry platform? That comparison should make the biggest cost difference visible early.

The zero-threshold door deserves its own drainage and weatherproofing allowance, rather than being buried in the door or finish budget. The door itself may not be the expensive part. A properly detailed sill pan, continuous exterior drainage plane, positive grading away from the opening, and often a covered approach can drive the cost.

I’d show that as a separate alternate alongside the regraded approach and ramp/platform options. The designer should also verify the finished exterior and interior elevations early, since a flush threshold leaves very little tolerance for paving settlement or water buildup. If the approach can’t reliably shed water without a roof or trench drain, that needs to be visible in the comparison before the slab and foundation elevations are fixed.

For the zero-threshold option, can the designer provide a section drawing showing the driveway, landing, sill, slab, and finished interior floor elevations, along with the intended drainage path? That would make the bid compare an actual buildable flush detail rather than allowances based on nominal elevations.

I’d also want the section to show where water is expected to go during heavy rain, including any trench drain, covered approach, sill pan, and connection to site drainage. With only an 18-inch overall rise, a small elevation change at any one of those points could determine whether the threshold is genuinely flush or whether the approach needs a ramped transition.

The possible future lift shouldn’t be treated as just blocking and conduit. For an 18-inch rise, have the engineer identify a realistic location and type now, even if the equipment won’t be installed:

- A platform lift needs a shaft or clear footprint, landing geometry, weather protection, and foundations or framing designed for its loads.
- A stair lift needs a stair layout and landing dimensions that leave usable clearance after the equipment is installed.
- A vertical lift may require a pit, overhead clearance, equipment space, and a route for drainage and power.

Blocking and an empty conduit are inexpensive while the structure is open, but they won’t help much if a future lift would land over a footing, lack a supporting wall, or require cutting through the slab and floor framing. I’d show the lift location and anticipated support loads on the structural drawings, then price the actual rough-in separately from the equipment.

The empty conduit for a future lift or door operator is useful, but it should be paired with an electrical-capacity allowance. Otherwise the conduit may terminate at a finished panel with no spare spaces, insufficient load capacity, or an inconvenient disconnect location.

I’d have the electrical drawings identify:

- A reserved breaker space, with the anticipated voltage and load noted.
- Panel and service capacity for the likely lift or operator, subject to the equipment manufacturer’s final requirements.
- A reachable disconnect location and a continuous, accessible route from the panel to the equipment.
- Separate provisions for controls, sensors, lighting, or communications if the selected equipment needs them.

For a door operator, the rough-in can often be modest. A lift is less predictable, so the structural location and electrical allowance should be based on a realistic equipment category rather than a generic “future lift” note. That keeps the conduit from becoming a false economy.

The section drawing and drainage allowance are useful, but I’d also make the governing accessibility dimensions explicit in the quote, not leave them to be inferred from “flush” or “wide.”

For each route segment, have the designer identify:

- Required clear door width, measured at the finished opening and hardware.
- Landing depth and width at the entry and any direction changes.
- Maneuvering clearances at doors, including the effect of nearby walls or cabinets.
- Maximum permitted running slope and cross slope for the intended route.
- Finished elevations and tolerances for thresholds and flooring transitions.

These dimensions should be fixed before framing, slab work, and door ordering. A small change in a wall location, trim detail, threshold, or finish buildup can use up the available clearance or slope tolerance. I’d ask the builder to show any dimension that isn’t being guaranteed as an allowance or alternate, rather than pricing a generic accessibility package.

I’d be cautious about showing all three buckets as equally deferrable. If the route needs to work from move-in, the base bid should cover one complete, usable accessible route; phasing a missing piece of sitework or a threshold rebuild can leave the whole route unusable until that work happens. Show optional equipment and finish upgrades separately, rather than treating gaps in the route as savings. That makes the lower initial price easier to compare with the actual cost of having access from day one.