Shed vs Gable vs Eyebrow Dormer: Toronto 2026 Comparison

# Shed vs Gable vs Eyebrow Dormer: Toronto 2026 Comparison

Once you've decided to add a dormer to your Toronto attic, the next decision is which type. The three options on the table for a 1.5-storey Toronto home — shed, gable, and eyebrow — differ in three things that matter: how much usable floor area they add, how much they cost, and how they read from the street. The "best" dormer is whichever of those three is most important to you for this specific renovation.

This post is the head-to-head comparison. For dormer pricing as standalone numbers, see [Dormer Addition Cost Toronto by Type](/blog/dormer-addition-cost-toronto-types). For full project budgets, see [Attic Conversion Cost Toronto: Tier-by-Tier Comparison](/blog/attic-conversion-cost-toronto-comparison). For the broader pillar, see [Attic Conversion Toronto 2026: Complete Guide](/blog/attic-conversion-toronto-2026-complete-guide).

The Three Dormers in One Sentence Each

• Shed dormer — single flat or low-slope roof, runs across the rear roof slope, adds the most usable floor area per dollar. Cost: $15,000 to $30,000.
• Gable dormer — peaked roof matching the main house slope, traditional aesthetic, the only choice for street-facing dormers in Heritage Conservation Districts. Cost: $20,000 to $40,000.
• Eyebrow dormer — curved arched roof, premium architectural feature, adds the least floor area but the most curb appeal. Cost: $30,000 to $60,000.

Side-by-Side: Floor Area Per Linear Metre

This is the variable that matters most for master-suite or office conversions:

A single rear shed dormer 8 m wide adds roughly 600 to 800 sqft of full-headroom floor area. To match that with gable dormers, you'd need three across at 4 m each — and the total cost would be 1.5 to 2 times the shed dormer cost.

Framing and Structural Complexity

Shed Dormer

Simplest framing. One ridge beam, two short side walls, one long front wall, simple flat or low-slope roof. The P.Eng beam is the largest structural cost — typically a single LVL or steel W-beam spanning the dormer width. No valleys, no hips. Roof tie-in is one continuous joint along the rear edge.

Build time: 5 to 8 working days for the structural shell, weather-tight.

Gable Dormer

Moderate framing. Each gable dormer has its own small ridge, two roof slopes, jack rafters, valley rafters, and two valley conditions where the dormer roof meets the main roof. Multiple gable dormers across a roof multiply this complexity. The P.Eng beam carries the existing main roof above each dormer cut, plus the gable dormer's own structure.

Build time: 6 to 10 working days per gable dormer for the structural shell.

Eyebrow Dormer

Most complex framing. Custom-cut curved rafters or laminated curved structural members, no vertical wall (the roof itself bends), tight roofing curves that require either custom-bent metal or specially-conditioned shingles. Specialty framing carpenters required, and not every Toronto contractor has done one. The P.Eng design is custom for each project.

Build time: 10 to 15 working days for the structural shell, sometimes longer if curved framing requires off-site fabrication.

Heritage Conservation District Impact

Toronto has several Heritage Conservation Districts where exterior alterations require a Heritage Permit before a Building Permit can be issued. The HCDs most relevant to attic conversions:

• Cabbagetown North and South — Victorian and Edwardian homes, strong street-side character preservation
• Old Riverdale — Edwardian and early 20th century streetscapes
• Wychwood Park — Arts and Crafts homes, very tight design controls
• Casa Loma — Eclectic but heritage-controlled
• Several smaller HCDs — Harbord Village, parts of the Beaches, Yorkville, etc.

Heritage Impact by Dormer Type

• Shed dormer (rear-only): Usually approved without significant scope changes because not visible from public realm. Heritage Preservation Services may still review, but timeline is shorter and design changes minimal.
• Shed dormer (street-facing): Often denied or scoped down. Heritage Preservation Services typically prefers gable dormers on street-side roofs.
• Gable dormer (rear or side): Approved with minimal scrutiny.
• Gable dormer (street-facing): Approved if proportions, materials, and detailing match the historic character. Expect requirements for matching window proportions, traditional trim, and matching brick or wood siding.
• Eyebrow dormer (any location): Reviewed on merit. May be approved if the home historically had eyebrow dormers (some Edwardian homes did), or denied if it would be a contemporary insertion into a Victorian or Arts and Crafts streetscape.

For full HCD guidance including the Heritage Impact Assessment process, see [Dormer Heritage Permit Toronto: HCD Restrictions](/blog/dormer-heritage-permit-toronto-hcd).

Cost Per Square Foot of New Habitable Space

This is the number that lets you compare dormer types on the same axis:

• Shed dormer: $25 to $50 per sqft of new full-headroom floor area
• Gable dormer: $80 to $180 per sqft (single) or $50 to $90 per sqft (three across, sharing setup costs)
• Eyebrow dormer: $250 to $1,500 per sqft (eyebrows add little area, so any dollar amount divides into a small denominator)

This is dormer-only cost divided by floor area gained. Total project cost (interior finishes etc.) is layered on top and is roughly the same per sqft regardless of dormer type.

When to Choose Shed

• The rear of your house is what matters and the front roofline stays untouched
• You want a master suite, large home office, or two-bedroom layout
• Your budget is the constraint and you want maximum floor area per dollar
• You're not in an HCD, or your HCD-facing roof slope isn't being touched

This is the right answer for the majority of Beaches, Junction, Mimico, and East York homes.

When to Choose Gable

• The dormer must be street-facing (corner lot, narrow lot where rear isn't accessible, or you want symmetry across the front)
• You're in a Heritage Conservation District and Heritage Preservation Services is going to require gable
• Your home is Edwardian or Victorian and aesthetically demands a peaked dormer
• You're willing to accept 1.5 to 2 times the cost per sqft for the visual harmony

This is the right answer for many Cabbagetown, Old Riverdale, and parts of Riverdale and Wychwood Park homes.

When to Choose Eyebrow

• The dormer is a signature design element and floor area is secondary
• Your home historically had eyebrow dormers (some Edwardian and Arts and Crafts homes did)
• You're working with a heritage architect who has specifically recommended this type
• Budget is not the primary constraint

This is rarely the right answer purely on space-or-cost criteria. Choose eyebrow when curb appeal is the priority and you're willing to pay the premium.

Hybrid Strategies

Many Toronto attic conversions combine dormer types:

• Front gable + rear shed. The street-side gable dormer satisfies HCD or aesthetic requirements; the rear shed dormer adds the bulk of the usable floor area. Common in Cabbagetown and Old Riverdale.
• Two front gables + rear shed. Multiple front gables for symmetry, single wide rear shed for master suite. Higher-end Beaches and Riverdale homes.
• Front eyebrow + rear shed. Eyebrow as a curb-appeal feature on the street side; shed for actual living space. Custom Edwardian homes in central neighbourhoods.

These hybrids cost more but solve the trade-off between aesthetics and floor area.

Window Sizing and Egress

OBC 9.9.10 requires every bedroom to have an egress window: minimum 0.35 m² clear opening, no dimension less than 380 mm, sill no higher than 1.5 m above the floor. Each dormer type accommodates egress differently:

• Shed dormer: Wide window or pair of windows, easy to meet egress on the long flat front face
• Gable dormer: Single window centred in the gable, must be sized large enough for egress (typically 800 mm wide x 900 mm tall minimum)
• Eyebrow dormer: The arched window itself must be sized for egress, which sometimes constrains the eyebrow design

For full egress detail, see [Attic Bedroom Conversion: OBC 9.9.10 Compliance](/blog/attic-bedroom-conversion-obc-9-9).

Resale Impact

Toronto Real Estate Board agents we work with consistently report:

• Buyers in non-heritage neighbourhoods are dormer-type-agnostic — they care about the resulting space, not the dormer style.
• Buyers in HCDs (Cabbagetown, Old Riverdale, Wychwood Park) actively prefer gable dormers and may discount homes with shed dormers visible from the street.
• Eyebrow dormers don't measurably increase resale value beyond the floor area they add — they're a use-pleasure feature, not a resale-value feature.

For full ROI analysis, see [Attic Conversion ROI Toronto: Resale Analysis](/blog/attic-conversion-roi-toronto-resale).

Decision Framework

Use this three-question test:

• 1. Is the dormer street-facing in an HCD? If yes, gable (or possibly eyebrow). If no, continue.
• 2. Is maximum floor area the priority? If yes, shed. If no, continue.
• 3. Is curb appeal worth a 50 to 100% cost premium? If yes, gable or eyebrow. If no, shed.

For most Toronto 1.5-storey homes, this resolves to: rear shed dormer for usable space, possibly with one or two front gable dormers if street-side aesthetics matter.

Next Steps

The right way to choose your dormer type is a feasibility visit: site assessment of existing roof slopes, photographs, HCD check, P.Eng span analysis, and a written recommendation that names the dormer type and cost tier appropriate for your specific home and goals.

[Book a dormer feasibility visit](/services/home-renovation/attic-conversion-dormer) — RenoHouse provides honest type-and-budget guidance before any design fees are spent.

Continue with the pillar: [Attic Conversion Toronto 2026: Complete Guide](/blog/attic-conversion-toronto-2026-complete-guide). Or see neighbouring topics: [Attic Conversion Cost Comparison](/blog/attic-conversion-cost-toronto-comparison), [Dormer Cost by Type](/blog/dormer-addition-cost-toronto-types), [Heritage Permit Guide](/blog/dormer-heritage-permit-toronto-hcd).