If you’re drawn to classic European silhouettes and the idea of turning attic space into a real living area, a mansard roof is worth considering. It’s the kind of roof that changes how a house feels the moment you see it. With various mansard roof types available, you can select a style that suits your home and budget.
A four-sided roof with two slopes on each side is called a mansard roof. It has a steep lower portion and a much gentler upper one. The steep part often includes dormers that bring in light, while the shallow top reads almost flat from the street.
More specifically, here’s how to spot one:
The steep lower slope opens up interior space, a common selling point for homeowners. A full mansard roof replacement ranges from $10,000 to $30,000, but custom jobs can double that number.
Roofing repairs on the steep sides typically cost between $700 and $3,200 for metal and between $800 and $3,200 for slate, with larger slate patches priced per square foot.
Homeowners usually choose among four common shapes. Each retains the two-slope idea, with the difference lying in the curve of the lower portion. These shapes affect the look more than the layout, but concave and S-curves can slightly reduce interior headroom where the curve tucks in.
The lower slope runs straight down, so the edges are crisp, and the dormers sit neatly. Installers work more efficiently on flat surfaces with standard panels or shingles. Good choice if you want clean lines and substantial perimeter headroom.
The lower slope bulges outward, creating a gentle “bell” effect. Panels and flashing require shaping, making labor more involved. Choose this option if you prefer a softer profile from the street and don’t mind a more customized installation.
The lower slope scoops inward, then flares at the eave. Curved cuts and trim slow the work, and edge headroom tightens slightly near the curve. It suits homeowners who want a refined, sheltered look around upper windows.
Starts concave and finishes convex, so there are two curve changes to detail. Expect the most custom fabrication and the longest install time. Best suited for a statement roof where craftsmanship and sculpted lines are integral to the appeal.
This type of roof may look decorative, but its structure is surprisingly practical. What matters most is the frame and how water gets off the roof.
A mansard roof has two distinct slopes on every side. Carpenters frame the lower slope almost like a wall, which adds height and defines the roof’s break point. Because of this extra framing, the job takes longer than a standard gable or hip roof, and you’ll want a builder familiar with this roof type to ensure solid support.
The top of a mansard roof is almost flat, so it needs a reliable way to move water off the surface. Older roofs often relied on basic coatings or tar, which crack or dry out over the years.
Today, most roofers use a membrane system. It’s a layer made from rubber that seals the surface and prevents leakage. If you’re repairing an older mansard roof, ask your contractor if membrane installation is included in their package.
The steep lower faces can be finished in several durable materials. Common choices include slate, architectural shingles, and standing seam metal. They fasten tightly to the roof’s surface so it won’t lift in high winds or get damaged in the rain.
The upper surface usually needs a different type of covering. Roofers often use single-ply membranes or coated metal systems here because these materials handle standing water and constant sun exposure better than shingles or slate.
The choice of window and cornice defines how traditional or modern your mansard appears. Larger dormers can flood upper rooms with light, while slimmer profiles keep the design understated.
If you’re aiming for a cleaner style, consider simplifying decorative moldings or using contemporary colors. These adjustments can modernize the look without altering the roof’s structure.
Due to the steep faces being difficult to access, installation typically requires scaffolding or lifts. This adds time and labor, especially if your home is more than two stories tall. So, expect the project to take longer than a conventional roof replacement.
Some neighborhoods and Homeowners Associations (HOA) have rules about roof height or exterior changes, especially if the property is historic. Before starting, confirm that your design and materials meet local requirements. A quick check early in planning can save you from redesigns later.
Every roof style has its strengths and quirks, and the mansard is no exception. If you’re considering one for your home, here’s what works in its favor, and what might take a little extra planning.
Adds Livable Space
The steep lower slopes create nearly full-height walls. That means you can turn the upper level into bedrooms, an office, or even a rental suite without expanding your home’s footprint.
Visually Distinctive
A mansard roof’s distinctive shape, especially when finished with quality materials like slate or metal, instantly draws attention from the street and gives the home a more refined look.
While specific resale lifts vary, properties that maximise upstairs space and architectural character typically command stronger buyer interest.
Flexible for Future Changes
Because the lower slopes are nearly vertical, the mansard’s frame can handle updates more easily than most roofs. Adding dormers, skylights, or even another small level usually doesn’t require tearing everything down. It’s a design that grows with your home, rather than locking you into a single layout.
Higher Cost
Expect a bigger number than a simple gable. Homes under 2,000 square feet typically cost between $18,000 and $28,000 for a full replacement. If your home is bigger or historic, a full mansard roof design can range from $30,000 to $50,000.
Why this jump? There’s more material to cover and more siding-like roofing to install. Every dormer, edge, or slope change adds labor. Most crews will also need scaffolding or a lift.
More Attention to Waterproofing
The top of a mansard roof is much flatter than it looks, and that’s where most homeowners run into trouble. Because water doesn’t slide off quickly, it needs a reliable way to drain. If water lingers after rain or snow, it can start to find weak spots in corners.
To avoid this, keep gutters and outlets clear and schedule a roof check every couple of years. A roofer can spot small cracks or loose seams before they turn into problems.
Needs Experienced Installers
Not every roofer handles mansards. The shape demands precision where the steep and flat sections meet. Look for past similar projects on the roofing company’s website.
You can manage some updates yourself. However, for more significant changes, you’ll want a professional. Below are clear steps to guide you.
Remove moss from shingles on the steep sections. Do not use excessive water; instead, use a low-pressure rinse to avoid leaks.
If your upper surface shows signs of age like curling shingles, rust, or cracks, it’s time to call a roofer. They’re qualified to evaluate the existing material condition and add a new waterproof layer.
Skylights or updated dormer windows can brighten the upper level and make it feel larger. These changes affect the framing and waterproofing, so they’re not a DIY task.
Ask your contractor about insulated glass and designs that maintain a balanced style.
Before updating your mansard roof design, check what’s allowed in your area. Start with your local building department. Most cities require a permit for major roof work or any visible change to your home’s exterior.
If you live in a historic district, you may also need approval from a preservation board, which can limit changes. Your contractor can often help you navigate these rules and choose products that meet local HOA standards while still giving your roof a modern look.
A mansard roof stands out for its four sides, each with two slopes, creating more usable upper-floor space than most roof types. This design is more detailed and labor-intensive, so it typically incurs higher costs.
Simpler roofs, such as gable or hip designs, are cheaper to build but offer less attic height. Flat and shed roofs cost less upfront, but require more maintenance over time.
Before committing to a mansard roof, make sure you have all practical questions answered.
To turn the top of the house into real rooms. The steep lower slopes act like tall perimeter walls, allowing you to plan bedrooms, an office, or a studio with standard furniture and windows, rather than low, awkward attic corners.
Gambrel vs. Mansard: What’s the Difference?A gambrel has two slopes on two sides, barn-style. A mansard has two slopes on all four sides, which wrap around the full perimeter and usually offer better headroom.
A dormer is a small roof extension with a window that adds light and headroom. A mansard is the whole roof style; dormers are often built into its steep sides for light and ventilation.
Steep sections in slate or standing-seam metal often run 40 to 60 years with routine care. A waterproof layer should be reapplied every 20 years or so. Clear drains and periodic inspections help you reach the long end of that range.
Yes. Roofers often cover the steep faces and replace the top waterproofing in the same project, and that’s a good time to add dormers or upgrade insulation.
Generally, yes. There’s more surface area, more flashing and edges, and access is harder on the near-vertical slopes.
For the steep sides, choose sturdy materials such as natural or engineered slate, metal shingles, or standing seam metal. These fasten securely and handle wind and rain well. For the top, use a waterproof membrane or coated metal.
If water can’t get off the roof or if the seams are neglected, yes. Keep gutters and outlets clear and have a roofer check the top layer every few years.
It can, especially when the upper level is finished as real living space and the exterior reads as well-kept and cohesive. Buyers respond to usable square footage plus a distinctive profile.
Yes — this is where it shines. The form creates full-height rooms rather than storage nooks, making it one of the easiest roof styles for converting the top level into everyday living space.
If you want more real space upstairs without expanding your footprint, this roof style earns a spot on your shortlist. Use this quick fit test before calling your contractor:
If the boxes check out, a mansard offers practical upstairs space and a memorable silhouette.
