Arched Windows: Half Moon, Eyebrow and Impact Options for Florida

Arched windows are windows with a curved top instead of a square one. The main types are the half moon (a half circle), the eyebrow (a shallow, gently curved arch), the quarter round and the round-top or arch-top window (a rectangle topped with an arch). They are usually fixed, non-opening units, and in Florida they can be replaced with impact-rated versions built to the exact shape of your opening.

Arched windows are common on Mediterranean-style and stucco homes across Southwest Florida, often over entry doors, sliders and large picture windows. Because each one is a custom shape, they need more careful measuring, ordering and installation than standard rectangles.

Types of Arched Windows

Half moon window

A half moon window is a half circle: its width is roughly twice its height. It is often set above a door, a pair of windows or a slider, and it is almost always fixed glass. Half moon windows can also be "extended," with short straight legs below the curve.

Eyebrow window

An eyebrow window has a flatter arch than a half circle, rising gently from the sides to a low peak, like a raised eyebrow. Eyebrows suit wide openings where a full half circle would be too tall, such as over a wide slider or a bank of windows.

Quarter round window

A quarter round is one quarter of a circle, often used in pairs on either side of a gable or beside other shapes.

Round-top or arch-top window

A round-top combines a rectangular window with an arched top in one frame or in two units joined together (mulled). The lower part may be a single-hung or casement while the arched part is fixed.

Full circle and other custom shapes

Full circles, ellipses, gothic arches and other specialty shapes are possible but are more custom and more expensive.

How Arched Windows Work

Most arched windows are picture windows: the glass is set in a fixed frame and does not open. Operable arched units exist but are uncommon and costly. When an arch sits above another window or door, the two are usually joined by a mullion. In hurricane country, that mullion must be rated too, because it carries wind load between the units.

Manufacturers build shaped windows from a template or precise field measurements. The radius, leg heights and overall width all have to be right, because a shaped frame cannot be trimmed to fit like a stock rectangle.

Pros and Cons

Pros

• Architectural character, especially on Mediterranean and Spanish-style homes.
• Extra daylight high on the wall, where privacy is rarely an issue.
• Can visually raise a ceiling or entry.
• Available in impact glass from major Florida manufacturers.

Cons

• Custom shapes cost more per square foot than rectangles.
• Longer lead times for ordering and replacement parts.
• Blinds and shades for curved tops are specialty items.
• Heat gain on sunny walls unless you choose Low-E glass.
• High units can be hard to clean and reach.

Impact Arched Windows in Florida

Most coastal Southwest Florida homes are in the wind-borne debris region under the Florida Building Code, 8th Edition (2023), so arched windows need impact protection just like rectangular ones. Shuttering a curved opening is awkward, which is one reason homeowners choose impact arched windows. Key points:

• Product approval: the shape, size, glass and anchoring must be covered by a Florida Product Approval or Miami-Dade NOA. Shaped products often have their own approvals and size limits, so confirm the approval for the exact shape on your quote.
• Design pressure: the window and any mullion must meet the design pressure for its location on the wall. Higher units and corners can see higher pressures.
• Mulled assemblies: an arch mulled to a door or window below must use a tested mullion or a combination approved together.
• Buck and stucco: older arched openings often have curved wood bucks that hold moisture. Inspect and replace rotted bucks during replacement.
• HOA rules: associations may require a specific frame color or grid pattern on arches.

How Much Do Arched Windows Cost?

Arched and other shaped impact windows fall within the typical Southwest Florida range of about $1,200 to $3,800 per opening installed in 2026, but they tend to land in the upper half of that range because of custom fabrication and extra labor. Typical guidance:

• Small half moon or quarter round over an existing window: toward the middle of the range.
• Wide eyebrow or large half moon: toward the upper end.
• Round-top assemblies (rectangle plus arch): often priced as two openings, or as one large custom unit at the top of the range or above.
• Arches over sliders: the arch is priced as a window; the door is priced separately, typically $4,500 to $14,000 for an impact slider.

Costs rise with grids, tinted or Low-E glass, colored frames, curved buck replacement and stucco repair around the curve. Ask whether the quote includes interior trim on the arch.

What Goes Wrong With Arched Windows

• Leaks at the curve: sealant along a curved head is harder to install and often fails first.
• Rotted curved bucks: water entering at the curve can rot the wood buck behind the stucco.
• Fogged glass: failed seals in older insulated units.
• Cracked stucco around the arch: movement and water intrusion at the curve show up as hairline cracks.
• Missing impact protection: older arched units are often plain annealed glass, and many homes never had a practical way to shutter them.

How Arched Window Replacement Works

Replacing a shaped window takes a few more steps than a standard rectangle:

• 1. Measure or template the opening. The installer records the width, leg heights and radius, or traces the curve onto a template, after checking the existing opening for square and level.
• 2. Confirm the approval. The shape and size are checked against the product approval and the design pressure for that wall before ordering.
• 3. Order and wait. Shaped units are custom-built, so lead times are usually longer than for standard windows.
• 4. Remove the old unit. The old frame comes out carefully to limit stucco damage around the curve.
• 5. Inspect and repair the buck. Rotted or damaged curved bucks are replaced; in block homes, anchoring points are checked.
• 6. Install, anchor and seal. The window is set, shimmed and fastened per the approval, then sealed and flashed along the curve.
• 7. Finish and inspect. Stucco patch, paint and interior trim are completed, and the permit inspection is passed.

On a round-top assembly over a door or window, the lower unit and the arch are often installed the same day so the mullion and sealing are done as one system.

Glass and Comfort Choices

Arched windows are often high on sun-facing walls, so glass selection matters. Low-E coatings reduce heat gain while keeping the view bright, and light tints can cut glare in rooms where the arch catches the afternoon sun. Insulated laminated glass adds another layer of comfort and sound reduction compared with single laminated glass, at a higher price. Grids (muntins) in a sunburst or colonial pattern can match the style of the house, but they add cost and need to match the rest of the windows if you are replacing in phases.

How to Choose: Questions to Ask Your Contractor

• Is this shape and size covered by the product's Florida Product Approval at my design pressure?
• If the arch is mulled to a door or window, what mullion or combined approval is being used?
• Will you make a template or field-measure the radius?
• Will you inspect and replace the curved buck if it is damaged?
• Is stucco repair and paint around the curve included?
• Fixed arch or operable? What are the cost and lead time differences?
• Which glass package helps with heat on this wall?

Frequently Asked Questions

What is the difference between a half moon and an eyebrow window?

A half moon is a half circle, with a height about half its width. An eyebrow has a flatter, gentler curve, so it is shorter relative to its width.

Can arched windows be impact-rated?

Yes. Florida manufacturers offer impact arched windows in common shapes. Confirm the approval covers your exact shape, size and design pressure.

Do arched windows open?

Most are fixed. Round-top units can include an operable rectangle below a fixed arch, and specialty operable arches exist but are uncommon.

Can I replace an arched window with a rectangle?

Sometimes, but it changes the exterior appearance and requires reframing and stucco work, and HOAs may not allow it. Most owners replace the arch with an impact arch.

How do you cover an arched window for privacy or sun?

Specialty arched shades and shutters exist. Many owners leave arches uncovered and use Low-E or tinted glass to control heat.

Bottom Line

Arched windows give Florida homes their character, but each is a custom piece. Choose an impact arch whose shape and size are covered by its product approval, insist on accurate measuring and buck inspection, and budget for the upper half of the typical window range.

Thinking about replacing arched or half moon windows? Call Prestigious Home Improvements at (941) 223-4875 for a free in-home estimate.