# Ontario Skylight Guide 2026: VELUX Installation, Flashing, Condensation vs Leaks and Costs

**URL:** <https://home.renovation.reviews/t/ontario-skylight-guide-2026-velux-installation-flashing-condensation-vs-leaks-and-costs/46933>\
**Category:** Ontario\
**Created:** [April 26, 2026, 7:36pm UTC](https://home.renovation.reviews/t/ontario-skylight-guide-2026-velux-installation-flashing-condensation-vs-leaks-and-costs/46933 "2026-04-26T19:36:25Z")\
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**Page:** 1

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**Author:** ![system](https://home.renovation.reviews/user_avatar/home.renovation.reviews/system/32/77_2.png) [@system](https://home.renovation.reviews/u/system)\
**Post date:** [April 26, 2026, 7:36pm UTC](https://home.renovation.reviews/t/ontario-skylight-guide-2026-velux-installation-flashing-condensation-vs-leaks-and-costs/46933/1 "2026-04-26T19:36:25Z")

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Skylights are a top renovation request and a top leak callback. The product rarely fails – improper flashing does. Here’s what to know for 2026.

**Fixed vs venting:**

- Fixed: light only
- Manual venting: cord/wand operation
- Solar-powered venting (VELUX most popular): auto-close rain sensor, no wiring required

Venting skylights cost $300-$800 more than comparable fixed units.

**Flashing: use manufacturer kit, not generic step flashing**  
Manufacturer-specific flashing kits are engineered for each product and roof pitch. Generic step flashing voids most warranties and is the leading cause of leaks.

**Condensation vs actual leak:**  
Warm interior air hitting cold skylight glass in Ontario winters = condensation that drips. Solution: verify curb insulation, seal interior shaft vapour barrier, keep indoor RH below 50% in winter. Triple-pane skylights reduce condensation.

**GTA cost ranges (2026):**

- VELUX fixed skylight (supply only): $400-$800
- VELUX solar venting (supply only): $800-$1,800
- Full installation (new penetration, light shaft): $1,500-$3,500/unit
- Like-for-like replacement (same opening): $800-$2,000
- Sun tunnel (tubular, no shaft): $600-$1,200 installed
- Total new VELUX venting project: $2,500-$5,500

_Ontario skylight and roofing questions at [home.renovation.reviews](https://home.renovation.reviews)_