Arched Window Replacement: Impact Arch Cost, Process and Pitfalls in Florida

Arched window replacement means removing an old half moon, eyebrow or round-top unit and installing a new window built to the exact curve of the opening. In Southwest Florida that new unit is almost always an impact-rated arch, and a typical installed price falls within the $1,200 to $3,800 per opening range, usually in the upper half because shaped windows are custom-made. The job takes more measuring and finishing work than a rectangle, but it is routine for an experienced impact window installer.

For an overview of the shapes and how they work, see our guide to arched windows. This article covers the replacement itself: when it is time, what it costs, how it is done and where quotes go wrong.

Signs Your Arched Window Needs Replacing

• Fogging or a milky haze between panes, which means the insulated glass seal has failed.
• Stains or bubbling paint below the curve inside the house, often from a failed seal at the arched head.
• Hairline stucco cracks radiating from the arch, which can point to water reaching the buck behind the stucco.
• Soft or rotten wood at the curved buck when you press on the interior trim or exterior edge.
• Plain annealed glass with no practical way to shutter the opening before a storm.
• Heat and glare from an old clear-glass arch on a west or south wall.

On many 1980s to 2000s homes in Charlotte, Sarasota and Lee counties, the arch is the last unprotected opening after the rest of the windows were upgraded years ago.

Arched Windows Exterior: What Changes Outside

Arched windows exterior details matter as much as the glass. On a block-and-stucco home, the arch usually sits in a curved wood buck fastened to the concrete block, with stucco wrapped to the frame. Taking the old unit out disturbs that stucco band, and the new frame may sit slightly differently. Expect a stucco patch along the curve and fresh paint on that wall, or at least on the patched area. Good installers protect as much of the existing finish as possible and blend the patch, but a perfect color match on faded paint is never guaranteed.

If the house has foam trim or a decorative band around the arch, ask whether it will be removed and reinstalled or replaced. Our article on exterior window trim on stucco covers those details.

Impact Arched Window Cost in 2026

Using the typical Southwest Florida range of $1,200 to $3,800 per opening installed, here is how arch replacements usually price out:

• Small half moon or quarter round over an existing window: typically mid-range.
• Large half moon or wide eyebrow: typically the upper end of the range.
• Round-top assembly (rectangle plus arch, mulled together): often priced as two openings, or as one large custom unit at the top of the range or above.
• Arch over a sliding door: the arch is priced as a window; an impact slider is separate, typically $4,500 to $14,000.

What pushes an arch quote up:

• Low-E or tinted glass, insulated laminated glass or privacy glass.
• Sunburst or colonial grids, colored frames and matching interior trim.
• Replacing a rotted curved buck, which has to be cut and laminated to the radius.
• Stucco repair and paint around the curve.
• Second-story or high transom work that needs scaffolding.

Replacing an arch by itself costs more per opening than doing it with other windows, because the setup, permit and finishing labor are spread over fewer units. Many owners add the arch to a larger impact window and door project for that reason.

How Arched Window Replacement Works

• 1. Inspect and measure. The installer checks the opening, records width, leg heights and rise, and often makes a full-size template of the curve.
• 2. Confirm the product approval. The exact shape, size, glass and anchoring must be covered by a Florida Product Approval or Miami-Dade NOA at the design pressure for that wall.
• 3. Permit. Window replacement in Southwest Florida requires a permit, and the approval documents go with the application.
• 4. Order. Shaped impact units are custom-built, so lead times are usually longer than for standard sizes. Get the current lead time in writing.
• 5. Remove the old unit. The frame is cut free with as little stucco damage as possible.
• 6. Repair the buck. Rotted wood is replaced, and anchor points in the block are checked.
• 7. Set, anchor and seal. The window is shimmed, fastened per the approval and sealed along the curve, with flashing integrated where the wall allows.
• 8. Finish and inspect. Stucco patch, paint and interior trim are completed, then the final inspection is passed.

Arch Window Replacement Pitfalls

• Measuring only width and height. Two arches with the same width and height can have different radii. A template or a measured rise at several points avoids a gap you have to fill with caulk.
• Ignoring the mullion. If the arch sits on top of a door or window, the connection between them must be a tested mullion or a combination approved together.
• Skipping the buck. Setting a new impact arch into a soft buck means the anchors have nothing solid to hold.
• Changing the shape without approval. Squaring off an arch changes the facade, needs reframing and stucco work, and many HOAs will not allow it.
• Forgetting the treatments. If you have custom arch shades, the new frame may change the glass size. Read our guide to arched window treatments before reordering.

Questions to Ask Before You Sign

• Does the product approval cover this exact shape and size at my wall's design pressure?
• Will you template the curve or field-measure the radius?
• Is buck replacement included, or priced only if needed?
• Is stucco patch and paint included, and how much of the wall?
• Who handles the permit and inspection?
• What is the lead time, and what is the warranty on installation?

Frequently Asked Questions

How much does it cost to replace an arched window?

In Southwest Florida in 2026, a typical impact arch replacement falls within $1,200 to $3,800 per opening installed, usually in the upper half of that range. Large or mulled assemblies can go higher.

Can I replace just the arch and keep the window below?

Often, yes, if the lower unit is in good condition and the arch is a separate frame. If they are one frame or share a mullion, both usually need to be replaced together.

Are impact arched windows available in every shape?

Common half moons, eyebrows, quarter rounds and round-tops are widely available. Unusual shapes and very large sizes may have limited approvals, so confirm before ordering.

How long does arched window replacement take?

Installation usually takes a few hours per arch plus finishing work. The longer wait is the custom order and permit, which vary by manufacturer and county.

Will my homeowners insurance care?

Many Florida insurers give wind-mitigation credits when every opening is protected. An unprotected arch can keep a home from qualifying, so ask your agent and keep the installation paperwork.

Bottom Line

An arched window is a custom piece, so the quality of the measuring, the approval check and the buck repair decides how it performs. Budget for the upper half of the typical per-opening range, include the stucco and paint in the scope, and treat the arch as part of your full exterior remodeling plan if other work is coming.

Want a straight answer for your own home? Call Prestigious Home Improvements at (941) 223-4875 for a free in-home estimate anywhere in Charlotte, Sarasota and Lee counties. Licensed CRC1327831.