Cost of Skylight Replacement in Ontario — ROOFNOW™ Guide

Skylight replacement is a common roofing upgrade in Ontario due to aging seals, condensation issues, heat loss, and water intrusion caused by freeze–thaw cycles. Because skylights penetrate the roof structure, replacement must be done with proper flashing, underlayment, and winter-ready installation techniques. This guide explains the true cost of skylight replacement in Ontario and the factors that influence pricing.

Average Skylight Replacement Cost in Ontario
Cost Breakdown (Materials + Labour)
Types of Skylights & Price Differences
Why Skylights Leak More in Ontario Winters
Skylight Replacement FAQ

Average Skylight Replacement Cost in Ontario

The average cost to replace a skylight in Ontario ranges from $1,200 to $3,800 depending on the skylight type, size, flashing requirements, and roof complexity.

Standard replacement ranges:

Basic fixed skylight: $1,200–$2,200
Vented skylight: $1,800–$3,200
Solar/remote vented skylight: $2,500–$3,800
Custom or oversized skylight: $3,500+

Skylight wells may need interior repair, which can increase total cost.

Cost Breakdown (Materials + Labour)

Skylight replacements include the skylight unit itself plus the flashing system, ice & water shield, and labour.

Material Costs

Fixed skylight units: $350–$800
Vented skylight units: $700–$1,800
Solar vented skylights: $1,500–$2,800
Flashing kit: $120–$300
Ice & water shield: $20–$50

Labour Costs

Labour typically ranges from $500 to $1,400 depending on:

Roof pitch (steeper = more setup and safety)
Interior well condition (repairs add cost)
Metal vs asphalt roof (metal requires more precision)
Flashing replacement (mandatory for all installations)

Improper flashing installation is the number one cause of skylight leaks in Ontario homes.

Types of Skylights & Price Differences

1. Fixed Skylights (Most Common)

Cost: $1,200–$2,200
Best for natural light without ventilation needs.

2. Vented Skylights

Cost: $1,800–$3,200
Open manually or electrically to release attic heat and moisture.

3. Solar Vented Skylights

Cost: $2,500–$3,800
Powered by a solar unit—popular for homes without wiring access.

4. Custom Skylights

Cost: $3,500+
Used for oversized openings or architectural features.

Why Skylights Leak More in Ontario Winters

Ontario’s climate creates ideal conditions for skylight leakage and condensation. Issues include:

Freeze–thaw cycles: Snowmelt refreezes around flashing.
Attic humidity: Warm indoor air rises and condenses on the glass.
Clogged weeping channels: Prevent water from draining properly.
Improper flashing or underlayment: A leading cause of leaks.

Many homeowners discover skylight leaks after rapid temperature swings or during spring melt.

Skylight Replacement FAQ

Should I replace the flashing when installing a new skylight?

Yes. Old flashing should never be reused during a skylight replacement.

Can skylights be replaced in winter?

Yes, but weather conditions may increase labour time.

Do skylights reduce energy efficiency?

Old or failed skylights may lose heat, but modern low-E glass units improve insulation.

Why do skylights sweat inside?

Indoor humidity condenses on cold glass surfaces—often a sign of poor attic ventilation.

ROOFNOW™ Closing Section

ROOFNOW™ provides Ontario homeowners with engineering-based roofing guidance, including skylight performance, flashing science, winter behaviour, and long-term structural considerations. Explore more at the ROOFNOW™ Knowledge Center, www.roofnowontario.com, or visit the ROOFNOW™ main website at www.roofnow.ca.

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