THE ESTIMATING ANSWER
For one existing roof opening, start with a defined scope and measurement basis. Measure the structural opening, roof covering type, pitch and interior reveal. Keep unit, manufacturer-matched flashing and interior finish allowance separate. Price the listed tasks separately and state the condition that would require a revision: Rotten curb or incompatible opening changes framing and waterproofing scope.
This guide uses a fictional project in Calgary, Alberta: One existing roof opening. Its matching estimate and PDF give each scope decision a visible CAD cost line. Use the document to understand the structure; verify the actual building, product schedule, labour and supplier inputs before preparing a client quote.
Skylight replacement: separate the roof opening from the glazing allowance
A skylight replacement quote should confirm whether the existing opening can remain and identify the exact replacement unit. Record the visible dimensions, roof covering, interior shaft finish and any signs of leakage for the roofer's review. A like-for-like replacement and an enlarged opening are different jobs even when the glazing area looks similar in a product catalogue or a photograph.
Keep the selected skylight, compatible flashing, removal, roof access, fitting and internal making good as separate allowances. Ask who checks the existing surrounding material and how discovered damage will be priced. Interior edge repair, complete shaft redecoration and structural alteration should each be described explicitly; they should not be inferred from the phrase replace one skylight on a quotation.
For a skylight replacement quote in Calgary, share the same roof photographs and opening information with each supplier. Confirm whether product measurement, temporary weather protection and waste removal are included. Compare the full installation scope before comparing the product allowance, and keep any concealed roof damage as a documented change trigger.
A separate worked planning example
Illustrative comparison: one existing opening, one selected replacement skylight and one matching flashing set. Count interior repair as its own measured or fixed allowance. This example does not set an opening size or establish that an old and new product are interchangeable.
Cost and scope questions
Can I quote a replacement using the visible glass size?
Use that measurement only as preliminary information. The installer must confirm the product dimensions, opening and flashing arrangement before selection or fabrication.
Does a skylight replacement include repainting the whole ceiling?
Only when named in the scope. A local interior edge-repair allowance is different from repainting the shaft or the whole room.
1. Define the measured job
Replace one roof window or skylight in the existing suitable opening, with matching flashing kit and interior edge repair. Measure the structural opening, roof covering type, pitch and interior reveal. Record the measurements and existing condition in the estimate before turning quantities into line items. The scope should make clear why this is a separate project from a broader renovation or maintenance quote.
Measurement basis: Measure the structural opening, roof covering type, pitch and interior reveal.
2. Build a product and labour schedule
Keep unit, manufacturer-matched flashing and interior finish allowance separate. This example has 7 distinct lines, including opening and access survey, temporary roof protection, old skylight removal. Use actual supplier prices and labour inputs for a customer job; the displayed amounts are fictional document inputs.
Selections to confirm: Keep unit, manufacturer-matched flashing and interior finish allowance separate.
3. Sequence the work and handoffs
Confirm product and safe roof access before removing the old unit. Show which task depends on access, a selected product or another trade. If that dependency is still open, label the price preliminary and identify the information needed before a firm quote.
Work sequence: Confirm product and safe roof access before removing the old unit.
4. Set a change boundary
Rotten curb or incompatible opening changes framing and waterproofing scope. The example excludes new roof opening, ceiling renovation or concealed structural repair. Record the discovery, agree the revised work and update the estimate before adding it to the job.
If the job changes: Rotten curb or incompatible opening changes framing and waterproofing scope.
Review the Canadian job address
Review access, grades, drainage and seasonal conditions at the property. Check utility locations, product availability and any local design or municipal requirements that apply to the real scope.
Count the actual units, site visits and selected products separately. A count in this example is a document input, not a substitute for inspecting the real property. The example amounts are fictional CAD document inputs, not current rates for Calgary, Alberta or another community. A site visit and current supplier information are needed to replace them.
Work through the itemized calculation
Check each extension of quantity and rate in the paired PDF. Two lines from this project are:
- Old skylight removal: 1 each × C$385.00 = C$385.00.
- Skylight unit allowance: 1 each × C$1,390.00 = C$1,390.00.
Adding all 7 rounded line amounts gives C$4,000.00. The PDF shows 0% tax and the same total before any markup. The sample shows 0% tax only to make the arithmetic visible. Determine any applicable GST, HST or PST and markup for the actual work before sharing a quote.
| Work item | Quantity | Unit rate | Amount |
|---|---|---|---|
| Opening and access survey | 1 job | C$330.00 | C$330.00 |
| Temporary roof protection | 1 job | C$305.00 | C$305.00 |
| Old skylight removal | 1 each | C$385.00 | C$385.00 |
| Skylight unit allowance | 1 each | C$1,390.00 | C$1,390.00 |
| Flashing kit allowance | 1 set | C$360.00 | C$360.00 |
| Installation and weathering | 1 each | C$820.00 | C$820.00 |
| Interior trim and cleanup | 1 job | C$410.00 | C$410.00 |
| Illustrative subtotal | C$4,000.00 | ||
Scope and pricing boundaries
Replace one roof window or skylight in the existing suitable opening, with matching flashing kit and interior edge repair.
Outside this example: No new roof opening, ceiling renovation or concealed structural repair.
Keep the product allowance, installation work and any unresolved condition visible as separate decisions. If access or the selected product changes, update the affected quantity or rate and explain the revision before the client relies on the estimate.
Before you send the estimate
- Measure the structural opening, roof covering type, pitch and interior reveal.
- Keep unit, manufacturer-matched flashing and interior finish allowance separate.
- Confirm product and safe roof access before removing the old unit.
- Rotten curb or incompatible opening changes framing and waterproofing scope.
Check the business, client, property, dates, line extensions and notes. The skylight replacement PDF example shows one way to present them. Its short PDF note lists the brief's scope exclusions; the fuller project limits above should guide your own scope.
Questions about this estimate
Which quantity controls this skylight replacement estimate?
Measure the structural opening, roof covering type, pitch and interior reveal.
When should this skylight replacement quote be revised?
Rotten curb or incompatible opening changes framing and waterproofing scope. No new roof opening, ceiling renovation or concealed structural repair.
MAKE THE NEXT ESTIMATE YOUR OWN
Build a skylight replacement estimate.
Enter the job scope in Estimates on iPhone or Android or start from an AI-assisted draft. Check every quantity, rate, allowance, client detail and note before exporting the PDF. Some app features may require an in-app purchase.
