Onward
The mansard is the four-sided, double-sloped roof you see on French-style homes, row houses, and grand old hotels. Each side has a steep, near-vertical lower slope and a flatter top — a design that turns the attic into a full living floor. It’s also, by a wide margin, the most expensive common roof shape to build. This guide explains exactly why, and gives you the real 2026 numbers.
How much does a mansard roof cost in 2026?
A mansard roof costs $14,000 to $45,000 to replace in 2026 — the highest of any common shape. Per square foot, expect $8.00 to $22.00 installed, including tear-off. Slate and tile mansards on historic or high-end homes reach the top of that range; even asphalt on a mansard costs more per square foot than on a simple roof.
The price comes straight from the geometry. A mansard has four sides, and each side carries two slopes — a steep lower section that’s almost a wall, plus a flatter top. That nearly doubles the surface area versus a gable of the same footprint, and the steep lower slopes must be staged and worked slowly, almost like vertical siding. More surface, more cuts, more flashing, more hours.
Key takeaway: A mansard runs 60–120% more than a gable of the same footprint — but it adds a full floor of usable living space. If you have one, replace in kind with a pro who specializes in the shape. Get a free Onward estimate and compare written quotes in about 60 seconds.
Mansard roof cost by material
Mansards often mix materials by slope — a decorative steep face plus a low-slope membrane on the flatter top. The table below shows typical 2026 installed ranges for the full mansard on an average 2,000 sq ft home, reflecting the shape’s high surface area and labor.
| Material (steep face) | Cost per sq ft (installed) | Typical total (2,000 sq ft home) | Lifespan |
|---|---|---|---|
| Architectural asphalt shingle | $8.00–$12.00 | $14,000–$24,000 | 25–30 yrs |
| Metal shingle / standing seam | $11.00–$18.00 | $20,000–$36,000 | 40–70 yrs |
| Clay or concrete tile | $12.00–$22.00 | $24,000–$45,000 | 50+ yrs |
| Natural slate | $14.00–$30.00 | $28,000–$60,000+ | 75–100 yrs |
| EPDM / TPO (flat top section) | $4.50–$9.50 | priced separately | 20–30 yrs |
Because the steep and flat sections are different jobs, a good quote prices them separately. Compare your face options in our metal roof cost guide and slate roof cost guide, and the top deck in our flat roof cost guide.
Mansard roof cost by home size
A mansard’s surface scales fast because every floor of footprint adds steep wall-like slopes. The table uses mid-grade asphalt on the steep faces plus a membrane top.
| Home floor size | Approx. mansard surface | Mansard replacement cost |
|---|---|---|
| 1,000 sq ft | 1,500–1,900 sq ft | $14,000–$24,000 |
| 1,500 sq ft | 2,200–2,800 sq ft | $18,000–$32,000 |
| 2,000 sq ft | 2,900–3,700 sq ft | $22,000–$40,000 |
| 2,500 sq ft | 3,600–4,600 sq ft | $28,000–$48,000 |
| 3,000 sq ft | 4,300–5,500 sq ft | $34,000–$58,000 |
Want the broader picture? See our roof replacement cost guide and the cost per square math behind every quote.
Why a mansard costs more than other shapes
The mansard sits at the top of the price ladder. Here’s how it compares with the shapes below it.
| Shape | Cost vs. a gable | Why |
|---|---|---|
| Gable (baseline) | — | Two simple slopes, least waste |
| Hip | +10–20% | Four sloped sides |
| Gambrel | +15–30% | Two pitches per side, two sides |
| Mansard | +60–120% | Two pitches per side, all four sides, steep wall-like slopes |
The mansard’s premium isn’t markup — it’s roughly double the roof surface, worked partly like vertical walls, in two materials. The flip side is that it adds a full floor of living space, which is why builders accept the cost.
What drives your mansard roof price
- Surface area. A mansard has nearly twice the roof of a gable on the same footprint — the dominant cost driver.
- Material mix. Decorative steep faces (slate, metal, designer asphalt) plus a separate membrane top.
- Steep-slope staging. Near-vertical lower slopes need scaffolding and slow, careful work, raising labor sharply.
- Dormers and detailing. Mansards almost always have dormer windows, each adding cuts and flashing — see our dormer cost guide.
- The flat top deck. Its low-slope membrane needs proper flashing and drainage; it’s the most leak-prone part.
- Tear-off and decking. More surface means more to strip and inspect; soft decking runs $2–$5 per sq ft.
Is a mansard worth the cost?
If you want the extra living space and the unmistakable French-style look, the mansard earns its price by adding a floor without expanding the foundation. If you already own one, replacing in kind preserves both the home’s character and the bonus room beneath it. The key is hiring a crew that has done mansards before — the steep-slope work and material mixing reward experience and punish guesswork. For the full design picture, see our mansard roof design guide.
Why homeowners price mansard roofs through Onward
Onward isn’t a roofing company — we’re the layer of trust on top of the local ones. Tell us about your roof and we match you with a few licensed, insured, background-checked pros who compete for your job with free, written quotes. On a job this size, three itemized bids side by side are worth far more than one rushed number. You compare, read reviews we re-verify yearly, and choose. Your information is never sold.
Every pro clears The Onward Shield, our license, insurance, and reputation check. See how we calculate our cost ranges.
Your next step
A range is a starting point — your real mansard price depends on surface area, material mix, dormers, and the condition of the flat top deck.
- In the next 60 seconds: Get a free Onward estimate and we’ll match you with vetted local roofers experienced with complex shapes.
- Before you sign: Make sure the quote prices the steep faces and the flat top separately, and lists dormer and flashing work.
- Comparing shapes? See how a gambrel roof and hip roof compare on price and complexity.
The homeowners who pay a fair price on a complex roof are the ones who compare a few honest quotes from pros who’ve actually done the shape before.
