Two floating stair quotes are comparable only after the scope has been normalized. Put the same stair type, measurements, engineering responsibility, steel fabrication, finish, treads, guard, freight, installation, protection, permits, and closeout requirements on one worksheet. Mark every line as included, excluded, an allowance, or unresolved. The lower total may still be the higher-risk proposal if important interfaces are missing.
This is the practical response to a common homeowner problem. Public discussions about high floating-stair estimates often produce conflicting reactions because the headline number says nothing about the stringer design, tread and guard scope, structural work, finish, freight, or installation. Compare deliverables before comparing totals.
Build one bid-normalization sheet
| Scope item | Quote A | Quote B | Question to resolve |
|---|---|---|---|
| Stair configuration | Included / excluded / allowance | Included / excluded / allowance | Mono stringer, cantilever, zig-zag, straight, landing, or turn? |
| Site information | Who verifies floor-to-floor height, opening, walls, and connection zones? | ||
| Engineering and submittals | Who provides calculations, drawings, revisions, and required seals? | ||
| Steel fabrication | What is fabricated, prepared, trial-fitted, and documented? | ||
| Finish | What preparation, coating, color, touch-up, and protection are included? | ||
| Treads and risers | Material, thickness, finish, attachment, templates, and field fitting? | ||
| Guard and handrail | System, infill, attachments, transitions, and responsibility? | ||
| Freight and unloading | Packaging, shipping, delivery access, lift equipment, and damage process? | ||
| Installation | Setting, anchorage, field welding, touch-up, coordination, and cleanup? | ||
| Permits and closeout | Fees, inspections, punch list, care information, and warranty documents? |
1. Freeze the same basis of design
Ask every bidder to price the same written basis. At minimum, identify the project location, stair configuration, floor-to-floor height, approximate opening, number of treads, landing or turn conditions, tread direction, guard direction, finish intent, and delivery constraints. If a design is still conceptual, say which dimensions are preliminary and who will verify them.
A quote for a mono-stringer stair with owner-supplied treads cannot be compared directly with a quote for a different stringer type that includes treads, glass, and installation. Normalize first. If an alternate could save cost or schedule, list it separately so it does not obscure the base comparison.
2. Assign engineering and measurement responsibility
Floating stairs connect architecture, structure, fabrication, and finish work. The quote should state who surveys the site, who supplies structural information, who prepares shop drawings, who reviews them, and who responds to field changes. It should also say whether professional engineering or project-specific seals are included when required.
The International Residential Code is a model-code reference, not a universal project approval. The jurisdiction's adopted code, amendments, permit documents, and reviewing authority control stair geometry, guards, handrails, openings, and loads. Ask each bidder to identify the information it needs from the design team rather than promising compliance from a rough photo.
3. Separate fabrication from surrounding construction
A useful proposal distinguishes the fabricated stair assembly from work performed by other trades. Ask whether the price includes templates, connection plates, shop welding, trial assembly, surface preparation, coating, hardware, packaging, and fabrication drawings. Then list building work such as concrete pads, wall reinforcement, blocking, embeds, floor repairs, drywall, paint, and finish carpentry separately.
Use a responsibility matrix:
| Interface | Owner / GC | Designer / engineer | Fabricator | Installer |
|---|---|---|---|---|
| Verified opening dimensions | Provide access | Confirm design basis | State tolerances needed | Field-verify if contracted |
| Connection zones | Coordinate trades | Define supporting structure | Detail stair interface | Install approved anchors |
| Finish protection | Control site | Specify finish | Apply shop finish if included | Protect and touch up if included |
| Punch list | Document acceptance items | Review design issues | Address fabrication items | Address installation items |
4. Treat treads and guards as their own scopes
“Treads included” is incomplete. Record species or material, construction, thickness, finish, nosing, templates, attachment method, field fitting, and replacement responsibility. Do the same for the guard and handrail: material, infill, finish, attachments, transitions, and who coordinates it with the stair.
If the bidder is pricing only the steel stair structure, make that exclusion visible on the first page. If another trade supplies the guard, identify who resolves the attachment points before fabrication. Late decisions at this interface can create both rework and schedule delay.
5. Normalize freight, delivery, and installation
Custom steel work can be priced at the shop, delivered to the curb, delivered to the building, or installed. Those are different scopes. Ask for packaging, freight terms, destination, unloading, storage, delivery access, lifting plan, damage inspection, and claim responsibility. Confirm whether taxes, duties, permits, and travel are included.
For installation, list mobilization, equipment, access, setting, anchorage, field welding, touch-up, temporary protection, cleanup, and final adjustment. A proposal that excludes site equipment or assumes unrestricted access should not be compared as if those costs disappear.
6. Compare schedule assumptions and change rules
Record the dates or durations for design information, site verification, shop drawings, approvals, fabrication, finish, shipment, and installation. Identify what starts each clock. A lead time measured from deposit is different from one measured after approved drawings and verified dimensions.
The Federal Trade Commission recommends getting multiple written estimates and making sure the contract describes the work, materials, completion expectations, and price. For a custom stair, also ask how revisions, concealed conditions, delays, storage, and field changes will be priced and authorized.
What to send Senmit for a comparable quote
Use the Senmit floating stair request form with the project location, rough opening, floor-to-floor height, stair configuration, tread and guard preference, photos or drawings, quantity, finish direction, and delivery access. Flag any dimension that is not final. If you need to clarify the file format or an unusual site condition first, contact Senmit. The goal is a project-specific scope, not a generic price per step.
Bottom line
Choose the proposal with the clearest complete scope and the best fit for the project team, not automatically the lowest total. A one-page normalization sheet exposes allowances, exclusions, and unassigned interfaces while there is still time to resolve them.
The illustrations in this article were generated for planning education. They are not product photographs, engineering drawings, testing evidence, or proof of code compliance.
