A useful siding bid tells you what happens before the new boards go up, what is included in the finished exterior and how surprises will be handled. Put each proposal against the same scope before comparing totals. An unanswered line is a question to resolve, not an automatic reason to reject the contractor.
By Siding Contractor Benchmark · Sources reviewed October 4, 2026
1. Define exactly what is being replaced
Use photos or a simple elevation sketch to identify every included wall. Mark dormers, gables, the chimney, garage and additions separately. Ask the contractor to identify areas that stay, including brick, stone, soffit or fascia. If only selected elevations are being replaced, clarify how the new work will meet the retained material.
Record the siding manufacturer, product, profile, finish and color. Include the trim material and dimensions. Keep upgrades as separate options so an attractive alternate does not obscure what the base bid contains.
- Does the price include every elevation shown in the proposal?
- Which siding, trim, soffit, fascia and gutters are retained, replaced or excluded?
- Which materials are specified, and what requires your approval before substitution?
2. Make tear-off and hidden repairs explicit
Ask whether the installer will remove the existing siding or install over it, what existing layers are known and what conditions would change that plan. Where damaged sheathing is uncovered, a replacement-board allowance alone may leave the cause of the damage unresolved. Building America guidance recommends investigating water entry and addressing damaged sheathing as part of a flashing retrofit.
Our suggested change-order process is simple: photographs of the uncovered condition, a written repair scope, a price or agreed unit rate, and your approval before additional work. Also agree on who protects an open wall while that decision is made.
- How much sheathing or trim repair, if any, is included?
- How will additional repairs be measured and priced?
- Who diagnoses recurring moisture damage before the wall is covered?
Sources: Building America Solution Center: Flashing at Bottom of Exterior Walls ↗
3. Ask how the water-management details connect
‘Housewrap included’ does not describe the entire wall. Ask for the proposed water-resistive barrier and how it connects to flashing at windows, doors, roof intersections and other penetrations. Building America’s window guidance emphasizes integrating flashing with the surrounding water-control layers and reviewing those details before siding covers them.
Request a progress-photo handoff that shows the prepared wall, repaired areas and key flashing locations. The purpose is to document what was done; a photograph does not replace a required inspection or prove that an assembly is correct.
- Which existing flashing will be retained, evaluated or replaced?
- Who coordinates siding work with roofing, gutter or window work?
- Which inspections or agreed review points occur before the siding is installed?
Sources: Building America Solution Center: Windows and Doors are Fully Flashed ↗
4. Separate installation, trim and finish responsibilities
Request the installation instructions for the exact product being quoted. For example, James Hardie publishes specific lap-siding joint-flashing guidance, while LP publishes separate application instructions for its prefinished accessories. A vague promise to ‘caulk everything’ cannot stand in for the appropriate product details.
For field-painted work, write down who paints, what is coated, how cuts and exposed edges are treated, and what preparation and touch-up work are included. For factory-finished products, ask how installation damage and cut ends will be handled under the product’s instructions.
- Are window casings, corner boards, fascia, soffit and mounting blocks included?
- Who removes and reinstalls lights, shutters, vents, downspouts and other attachments?
- What remains for a painter or another trade after the siding crew leaves?
Sources: James Hardie: Lap siding installation tips ↗ · LP SmartSide: ExpertFinish accessory application instructions ↗
5. Include site protection, disposal and closeout
Ask where materials and the disposal container will sit, how entrances and landscaping will be protected, and who handles daily debris collection and final cleanup. Identify disposal charges and any work involving suspected hazardous materials before accepting a removal allowance.
For a home built before 1978, raise painted-surface disturbance at the first meeting. EPA recommends a lead-safe certified contractor for relevant renovation work. Ask the bidder to explain the applicable assessment, work practices and cleanup scope; do not assume newer outer siding resolves the question about older layers.
- Who obtains any needed permits and schedules inspections?
- What is the plan for weather interruptions and overnight wall protection?
- Will closeout include warranty documents, product information, photos and a final punch list?
Sources: EPA: Renovation, Repair and Painting for consumers ↗ · EPA: Newer siding over old painted surfaces ↗
6. Compare the agreement before the total
The FTC recommends multiple written estimates and a contract that records the work, materials, timing and promises made during sales conversations. Ask the contractor to reconcile a major price difference in writing. Record the payment schedule and the conditions for completion.
For your final comparison, mark every scope line ‘included,’ ‘excluded,’ ‘allowance’ or ‘unanswered.’ Resolve the unanswered items with each bidder. Then compare the base price, options and exposure to extra work. This worksheet is a way to organize decisions; it does not estimate a fair market price.
Sources: FTC: Hiring and comparing home-improvement contractors ↗
Questions before you hire
Should I automatically choose the lowest siding quote?
Compare what the quotes include first. The FTC recommends obtaining multiple estimates and asking for an explanation when their prices differ substantially. A smaller total may cover a different scope.
How should hidden rot be handled in a proposal?
Ask for the included repair allowance, any unit pricing, the documentation required and the approval process for additional work. Also ask who investigates the water-entry problem before repaired areas are covered.
Building America Solution Center: Exterior-wall flashing retrofit ↗
Build your shortlist
Compare local installers, then use the source links and questions above to request bids for the same scope.