Compare proposals against one agreed fixture list and layout. Then check the water-supply, drainage, venting, equipment, access, restoration and finish-connection scope line by line. Keep allowances and exclusions visible. A lower stated price does not establish a lower cost for the same completed work when important items remain unknown.
Why can two reasonable bids look so different?
One may cover rough-in plumbing only. Another may include fixtures and a finish visit, concrete restoration or a pump system. A remodeler’s proposal can include the rest of the bathroom. Start by naming the intended result and removing the ambiguity before comparing the amounts.
Illustrative scope comparison: Bid A covers moving a toilet drain, rough-in piping and an inspection. Bid B covers those items plus setting the toilet and vanity after the room is finished. Neither description establishes who supplies the fixtures or restores the floor. Ask both bidders to clarify those same omissions. Do not infer them from the price difference.
Use this sample plumbing scope worksheet
This is a planning aid, not a legal contract or a description of any contractor’s standard terms. Replace each prompt with the actual agreed scope and keep the referenced layout and fixture schedule with the proposals.
| Scope item | What to record |
|---|---|
| Project and layout | Address/jurisdiction, room area, dated drawing and agreed fixture locations |
| Fixtures | Fixture list, models if known, owner or contractor supply, connection responsibility |
| Existing work | What is retained, removed, abandoned, relocated or still subject to verification |
| Water supply | New and altered supplies, shutoff work, access and testing responsibility |
| Drainage | Connection route, fixture drains and unresolved concealed conditions |
| Venting | Included modifications and access outside the bathroom |
| Pumped system | Equipment model, basin, controls/alarm, discharge, vent and start-up scope |
| Electrical | Power for equipment, electrician responsibility and applicable approvals |
| Concrete | Opening, excavation, backfill, slab restoration and agreed finished condition |
| Permits | Applicant, permit holder, fees and inspection scheduling responsibility |
| Visits | Rough-in and finish visits, readiness conditions and return-trip treatment |
| Protection | Access route, dust-control discussion, debris removal and cleanup |
| Completion | Testing, approvals, equipment records, manuals and concealed-work photographs |
| Other trades | Framing, drywall, waterproofing, tile, flooring, cabinets and painting |
| Price qualifications | Allowances, exclusions, unknowns and change-order triggers |
Use the downloadable scope worksheet at a site visit, or enter proposal details in the interactive comparison tool.
How should allowances be compared?
Record the allowance amount, what it covers and whether it is already included in the stated contract total. An included allowance must not be added a second time. If its treatment is unclear, mark that uncertainty rather than assuming either inclusion or exclusion.
Ask what happens when the final selection costs more or less than the allowance. Material cost, labor, tax and installation accessories may have different treatment. Keep the contractor’s explanation with the comparison rather than relying on an informal memory of the conversation.
The costs and scope guide includes a hypothetical arithmetic example. It uses invented numbers to explain the calculation and does not represent local market pricing.
What should remain explicitly unknown?
Concealed pipe condition, an unverified route, an undecided fixture and an unassigned restoration task should remain visible until resolved. A blank line means the proposal has not answered the question. It does not mean the work costs nothing or is automatically included.
Ask each contractor which investigation would resolve the uncertainty, when it will occur and how a resulting change is priced and authorized. This creates a usable comparison even when no contractor can honestly fix every hidden-condition cost before assessment.
Who owns inspections and completion testing?
Name the permit holder and the person scheduling inspections. Ask what must stay exposed and what evidence releases the next stage. In Overland Park, the current residential amendment assigns required plumbing tests to the permit holder, including the equipment, materials and labor needed for testing. See section 16.310.P2503.3.
That does not establish the schedule for every project. Use the permit comparison to identify the authority and confirm the actual checkpoints. The construction checklist helps attach responsibility to each stage.
Compare the contractor’s explanation as well as the amount
Look for a clear scope, an understandable reason for the drainage approach, product compatibility, a workable coordination plan and a specific treatment of uncertainty. Verify the credentials applicable to the contractor and jurisdiction independently. This website does not rate or select contractors from the figures you enter.
Start with bathroom rough-in scope, drain relocation or sewage ejector projects as appropriate. If you are still defining the project, return to the complete guide before requesting comparable proposals.