How to compare exterior remodeling estimates
Two estimates for the same job are thousands apart. How do I tell what I'm actually comparing?
Compare the scope line by line before comparing totals. A price difference may reflect materials, preparation, access, finish work or how uncertainty is handled; an omitted description needs clarification before you treat it as excluded.
Line up the measured quantities, named products, preparation and cleanup, exclusions, and process for additional work. Ask each contractor to put missing details in writing so the final proposals describe the same job.
Start with the scope, not the total
Exterior work is priced by what is done, and two contractors rarely describe the same job the same way. One estimate may replace all the trim; another may reuse it. One may include priming bare wood; another may assume the paint covers it. Neither is wrong on its face, but they are different jobs.
Read each estimate and write the tasks in a simple list. Then check what one includes that the other does not. The gaps are usually in preparation, hidden-damage handling, and finish work, and they are usually where the price difference lives.
Five things every complete estimate makes clear
- The work included: each task, by wall, opening, or roof section.
- The materials proposed: product type, profile or grade, and finish, specific enough to look up.
- The preparation and cleanup: what is protected, what is removed, and what the site looks like at the end of each day.
- Any exclusions: what is not in the price, such as painting, permits, or interior finish.
- How changes are handled: what happens when hidden damage appears or you change a selection, and how that is priced.
A worked example: two siding estimates with different scopes
Consider this illustrative comparison for replacing siding on an older Sacramento-area house. These are example scope descriptions, not actual bids or 916 Exteriors prices. The floor area of the house does not establish the wall area to be replaced; both contractors still need the same measured elevations and opening schedule.
| Line | Estimate A (lower) | Estimate B (higher) |
|---|---|---|
| Siding material | "Fiber cement lap siding" | Fiber cement lap, 8.25-inch smooth, primed; brand and profile named |
| Water-resistive barrier | Not mentioned | New barrier over all walls, taped seams |
| Window and door flashing | Not mentioned | New head flashing and sill pan at every opening (14 openings listed) |
| Trim and corners | "Reuse existing trim" | New corner boards and window trim, primed fiber cement, sizes listed |
| Sheathing damage | Not mentioned | $X per 4×8 sheet, approved before installation |
| Paint | "Paint included" | Coating system, surface preparation and finish coats named; joint treatment follows product instructions |
| Cleanup and disposal | Not mentioned | Daily cleanup, dumpster, magnetic sweep |
| Permit | Not mentioned | Authority and required application named; responsibility and fee allowance stated |
What the worked example shows
Estimate A may reflect a contractor who intends to include flashing and barrier work but has not described it. Ask for those details before treating an omission as an exclusion. Estimate B is more explicit, yet a longer description does not by itself prove better work or justify every price difference. Have both bidders confirm the same material, elevations, flashing, trim, sheathing allowance, finish and cleanup. Once the scopes match, compare the totals and ask about any remaining difference without assuming that the lower bidder has necessarily left something out.
The same exercise works for every trade. The siding, window, roofing, painting, gutter, and dry rot pages on this site each list what a written scope for that trade includes, so you can use them as a checklist against any proposal.
What to look for, trade by trade
- Siding: the water-resistive barrier and flashing at every opening; which trim is replaced; a per-sheet sheathing rate; whether paint is in scope.
- Windows and doors: insert or full-frame for each opening and why; the product and its NFRC energy values; who handles the permit; interior finish work.
- Roofing: tear-off or overlay; underlayment type; every flashing, vent, and pipe boot being replaced; a per-sheet sheathing rate; how gutters are handled.
- Exterior painting: every surface named; how failed coating is removed; what is primed; number of finish coats; how rot found during prep is priced.
- Gutters: gutter size and material; downspout count and where each discharges; fascia repair; the guard type and the cleaning it still needs.
- Dry rot and trim: each damaged piece mapped; the replacement material; the flashing or sealing change that stops the water; a unit rate for damage found behind the visible piece.
What California requires in the contract itself
Check whether the document is a preliminary estimate or the agreement you are being asked to sign. California sets minimum terms for home improvement contracts. The Contractors State License Board's consumer guidance states that a written contract is required for home improvement work over $500, and that the down payment cannot exceed $1,000 or 10 percent of the contract price, whichever is less. The contract should carry the contractor's license number, a description of the work and materials, the total price, approximate start and completion dates, a schedule of progress payments tied to work completed, and the notices about your right to cancel and about mechanics liens.
If the preliminary estimate lacks dates or a license number, request the complete contract information and verify the contractor before signing. A deposit above the applicable state limit needs correction, not an explanation based on the project’s total price. Do not assume that the other proposal is compliant merely because the first one has a problem; review both agreements against the same requirements.
Questions worth asking before you sign
- What happens if you find rot or damaged sheathing once the work starts? Is it priced per unit now, or estimated later?
- Which parts of this scope are done by your own crew and which are subcontracted?
- Is a permit required, and who pulls it and schedules inspections?
- What is the expected sequence of work, and who is my point of contact while it is underway?
- Which manufacturer instructions or warranty terms apply to the material you are proposing?
- If I change a selection after signing, how is the change priced and documented?
Request an estimate for exterior work
Common reasons two estimates differ
| Item | One possible scope | A different scope to compare |
|---|---|---|
| Preparation | Wash and paint | Scraping, repairs, priming bare wood |
| Hidden damage | Not mentioned | Per-unit price for sheathing or rot repair |
| Trim and details | Reuse existing | Replace with new, flashed material |
| Windows | Insert into old frame | Full-frame with new flashing |
| Gutters with a roof | Left in place | Removed, reinstalled, or replaced |
| Cleanup | Debris left for homeowner | Haul-away and nail sweep |
Red flags
- A total with no line items, or a scope that fits on one line.
- No mention of what happens when something unexpected is found.
- Pressure to sign today for a price that disappears tomorrow.
- Materials described only by brand slogan, not by product.
- A deposit request above the state limit, or no start and completion dates.
- No license number on the estimate. In California, the Contractors State License Board lets you check any license online, including whether it is active, bonded, and carries workers' compensation.
Build one comparison sheet with an unknown column
Use one row for each elevation, opening, roof section or drainage run and put the two proposals beside it. Add a third column for unanswered questions. Mark an omitted item as unknown, rather than zero dollars or excluded, until the contractor confirms it. An incomplete description may conceal a real difference, but it can also be a writing omission that a revised proposal resolves.
Keep quantities and units visible. A roof measured by surface area is not comparable with a figure based on the floor area of the house. A window count is incomplete without sizes and operating styles. A gutter length needs its outlet and downspout schedule. Ask the bidders to resolve these measurement differences before you calculate any per-unit comparison.
Record the date of each revision and the selections it assumes. When one contractor changes a product, color or repair allowance, the previous comparison is no longer current. Save the final proposal and its attachments together so that the description you reviewed is the description that accompanies the agreement.
Separate allowances from a complete fixed scope
An allowance is a budget assigned to an item that is not fully selected or known. Ask what the allowance covers, how the actual charge will be calculated, and what happens if the final choice costs less or more. A low allowance can make the initial total attractive without changing the eventual cost of the selected work.
Concealed damage is a different uncertainty. Ask how the contractor will document a discovery, who approves additional work, and what temporary protection is included while the decision is made. Unit rates can help with repeated work such as an additional sheet of sheathing, but an altered structural connection may need an individually defined scope rather than a simple multiplier.
Have both proposals describe the same initial investigation and repair boundary. One contractor may include limited opening and restoration, while another assumes the wall is ready for installation. Neither uncertainty disappears because the total is presented as fixed. The comparison should show what is known, what is allowed for, and what remains subject to a written change.
Compare completion and warranty responsibilities
Ask what has to happen before each trade is considered complete. For windows, that may include operation, screens, finish repairs and permit closeout where required. For gutters, it includes the agreed outlets and discharge locations. A coating job needs an agreed treatment of repaired surfaces and a clear cleanup boundary. Use the actual project scope rather than a generic promise of satisfaction.
Read the product warranty separately from the installation warranty. Identify the issuing company, the covered work, exclusions, claim procedure and any maintenance obligations. A long product warranty does not explain who will investigate a leak at a transition or pay to remove and reinstall adjacent material. Ask those questions while the competing scopes are still open for revision.
Finally, compare the working relationship: who communicates changes, how access is coordinated, and how incomplete items are recorded at the final walkthrough. These are practical purchasing criteria even when the product and price are similar. A clear closeout list helps you evaluate the finished work against the written agreement instead of relying on different memories of the sales conversation.
Request an estimate for exterior work
If the project is split into stages, compare the interfaces
A phased proposal needs more than separate prices. Ask what each stage leaves behind for the next contractor and which temporary details are included. For example, a window project followed by siding should explain how the new opening will meet the later barrier and trim work. A roof project followed by gutters should identify what happens at the drip edge and fascia in between. The goal is a complete, weather-protected assembly at the end of each stage.
Have the two bidders identify work that would be repeated if you split the project. Access equipment, removal of recently installed trim, paint touch-up and remobilization may appear in different places in their proposals. Ask for those costs to be described rather than assuming that buying every trade together always produces a discount. Some jobs can be separated cleanly; others share an important detail that needs one coordinated plan.
Discuss responsibility for the junction between trades before work starts. If a later crew needs to remove an earlier installation, establish who approves the method and who restores the affected finish. Retain photographs of concealed work and the approved product information so the next stage can be planned from evidence. These records make it easier to compare a combined proposal with a phased approach without treating either option as automatically superior.
What to do next
Ask each contractor to fill in the missing pieces so both estimates describe the same job. Then compare totals. If you would like a written scope from 916 Exteriors to compare against, request an estimate and tell us what you are noticing on the house; the how it works page explains what happens after you do.