Specialty Shape Window Cost in 2026: Arches, Half-Rounds, Circles, and Rectangle Comparisons

Installed price depends on the geometry being ordered

TruePane's Columbus, Ohio, custom-shape page publishes $400–$750 per small round-top or arch transom installed, up to 24 inches wide, and $600–$1,100 per medium eyebrow or half-round installed, 24–48 inches wide. Its table describes standard double-pane insulated glass and prices rough-opening repair separately. These are the service company's regional published estimates, checked September 30, 2026; the visible article does not give a publication date.

A different regional publisher, Window Replacements of Frisco, Texas, gives a $1,200–$1,600 installed example for a 4-by-4 picture window and $2,800–$5,500 installed for a half-round or arch with the same square footage. That is an equal-area comparison. It does not document an arch and rectangle with identical outside dimensions, the same ordered glass package, and the same opening work.

Keep those boundaries visible. A small Ohio transom and a larger Texas feature window are different purchases. The Frisco site's footer describes a platform connecting customers to professionals through fulfillment partners; its numbers are published planning examples, not an independently audited record of its own installation contracts.

Use the picture-window cost guide for rectangular fixed glazing and the window styles guide to compare operation. This page examines the shape premium, manufacturer shape schedules, and the difference between a fixed arch and a specifically documented operating arch.

Regional installed examples by shape

Sources: TruePane's visible Columbus installed-price table and Frisco's pricing-and-lead-times section. No row prices a particular Marvin or Andersen line. The plus sign in the circle estimate belongs to the source and is not a firm maximum.

The sources do not supply enough matching project detail to calculate a national shape surcharge. Ask for local alternatives that identify dimensions, glass, operation, access, and restoration. A regional estimate can frame that discussion; it cannot establish whether your proposed circle should cost more than somebody else's larger half-round.

Make the rectangle comparison explicit

“Same size” needs a written definition. Ask whether the rectangle comparison uses the outside frame's width and height, visible glass area, or the surrounding wall opening. Have the supplier label the chosen basis on both drawings before presenting a price difference.

Frisco's published example explicitly compares equal square footage. Repeating it as an equal-width-and-height comparison would change the source's claim. It also spans brand and glass choices, so subtracting its endpoints would not produce a verified premium for changing only geometry.

For a useful local comparison, ask the same seller to price the shaped and rectangular alternatives with the same material, glazing specification, finish, and installation scope. Request separate line items for any change to the opening or exterior finish. Those items belong to the project even if they disappear from a window-unit price.

If the proposed rectangle would occupy an existing curved opening, have the contractor draw the finished infill, trim, and exterior treatment. Ask who designs and supplies that work and how it connects to the surrounding wall. Compare the completed alternatives, rather than assuming a cheaper rectangular product automatically creates a cheaper finished project.

Why the two regional sources differ

TruePane's small-transom row includes a width boundary; Frisco's comparison uses a much larger rectangular example and equal-area specialty glazing. Their labels alone rule out treating the numbers as competing quotes for the same window.

The scopes also differ. TruePane identifies standard double-pane glass and separately quoted rough-opening repairs. Frisco says its written quotes include templating, fabrication, installation, and trim work, while its example varies with brand and glass. Those differences identify questions to ask; they do not prove a numerical adjustment between Columbus and Frisco.

Neither visible body gives a publication date. The retrieval date establishes that these examples were checked during this review, not that the publisher collected new transaction data on that date. Ask a local estimator to date its actual proposal and identify how long the price remains available.

Avoid averaging these regional rows into a synthetic national figure. A dated, measured proposal for your opening is the evidence needed to move from planning to buying. Preserve each alternative's scope so the reasons for a higher total can be reviewed without inventing a brand price table.

Manufacturer PDFs: similar curves, different product families

I opened Marvin's Essential catalog, its Elevate/Essential performance manual, and Andersen's manufacturer-hosted 400 Series Product Guide. The comparison below distinguishes the actual shapes and construction documented in those PDFs.

Sources: Marvin catalog, printed pages 26–27; Marvin performance manual, Prod Perf-16; Andersen guide, printed pages 117–118; Andersen circle sizing PDF; Andersen specialty product page; and the warranty PDFs discussed below. The last row is my purchasing interpretation of those documents.

A circle is not automatically available in every specialty line

The Essential catalog's illustrated polygon schedule includes triangles and an octagon. Its Round Top schedule includes particular curved profiles. These are separate documented options. A brand's general ability to make unusual windows does not establish that every line offers a full circle or your existing eyebrow radius.

Andersen's specialty guide separately names circles, ovals, and half circles. Ask the supplier to identify the exact family and model code for the desired profile. That answer should accompany the quote and remain on the final order.

If the supplier proposes a polygon to approximate a curve, review the drawing as a changed design. Ask to see the exterior elevation, glass outline, trim, and grille pattern together. Approve the actual proposed geometry rather than relying on a product-family name.

Likewise, ask whether “arched” describes one window with an arched head or a fixed half-round above a separate rectangle. The components, connections, and operation need to be identified before a price can be compared. A photograph of the finished elevation may conceal those distinctions.

Published size limits need their original qualifiers

Marvin's Essential catalog qualifies the Round Top dimensions by shape. Do not combine the largest width and largest height into permission to order that pair. The polygon description has both an area limit and a longest-leg limit; satisfying one does not establish the other.

The performance manual lists Essential Direct Glaze Round Top rows with Max Frame Size of 83 by 83 inches and 87 by 50 inches, each with CW-PG50-FW and fixed operation. Those entries belong to the identified rated product rows. They should not be renamed universal dimensions or guaranteed ratings for every custom curve and assembly.

Andersen's circle sizing sheet illustrates another distinction: CIR20 has an outside frame dimension of 2 feet 0-1/8 inch, a minimum rough opening of 2 feet 0-5/8 inch, and unobstructed glass of 19-3/4 inches. These labels describe different dimensions of the same documented model.

The sheet also warns that rough openings may need enlargement for wraps, flashing, sill panning, brackets, fasteners, or other items. Ask the seller to show the project-specific fit and selected installation arrangement. A catalog dimension alone does not settle the opening work or the installed total.

Fixed versus operable: specify the operating model

Andersen's current 400 Series Specialty page describes stationary windows used alone or combined with venting windows. A half-circle transom above a casement can therefore describe a combination in which the rectangle opens and the curved unit stays fixed.

An actual operating arch is a different documented option. Marvin's Ultimate Casement Round Top architectural manual has separate operable standard-size schedules, egress-and-vent-opening sections, and operating versus stationary/picture section details. That manufacturer PDF establishes that operating round-top products exist without implying that Essential fixed products open.

Request the operating model, shape code, handing, hardware, and permitted size on the order. Ask for a drawing showing the sash in its open position and the location of controls. Include curtains, furnishings, exterior obstructions, and access to the window in the review.

No fetched installed-price source isolates a matched fixed-to-operable upgrade within one manufacturer line. Ask the seller to provide that alternative directly. Keep any hardware, screen, structural, or finish differences with the total so a functional upgrade is not reduced to an unsupported generic surcharge.

Template and approved drawing come before fabrication

Frisco's measurement description identifies radius, spring-line offsets, and chord lengths for arches, plus widths and angles for trapezoids. TruePane's process description describes physical templates for curved or compound shapes. These are the publishers' stated processes, not evidence that every catalog shape requires identical custom fabrication.

Ask the seller to supply an approved drawing tied to the measured opening and quoted product. Identify the orientation, reference dimensions, curve or angles, and intended installation clearance. For a template-based order, ask who makes the template and who accepts it before fabrication starts.

Include the grille pattern, glass, interior finish, and exterior finish in that approval. Have the supplier draw how the shaped glass aligns with adjacent units. A changed grille or frame profile deserves review before it becomes an irreversible custom order.

Assign responsibility for a measurement or fabrication mismatch in the contract. Ask who remakes the unit, who handles temporary protection, and what happens to the installation schedule. Record those answers with the accepted drawing rather than assuming the manufacturer, dealer, and installer have made the same promise.

Joining an arch to another window is a separate specification

Andersen's guide, printed page 126, gives different joining details for a casement half-circle over a casement and a double-hung half-circle over a tilt-wash double-hung. Its notes say the illustrated details do not represent installation methods or materials and direct readers to the actual installation guides.

Request the complete assembly drawing and joining method for the proposed combination. Ask whether the factory or installer supplies the join and whether the price covers all components. Have the contractor identify the support between openings and the responsibility for its design.

Marvin's warranty exclusions specifically name field mulls. That makes a distinction between factory and field assembly relevant to the coverage conversation. Ask for the applicable written warranty answer for the proposed connection.

Preserve the whole assembly specification when comparing prices. A fixed upper arch priced on its own cannot establish the cost of the lower operating window, connecting parts, trim, and installation. Ask the bidder to identify whether its total buys one component or the completed combination shown on the elevation.

Warranty terms: duration and remedy need separate readings

Sources: Marvin warranty, glass and exclusive-remedy provisions and Andersen warranty, pages 1–2. These are document terms, not promises that every configuration receives every listed benefit.

Marvin's PDF uses overlapping boundary wording at 60 square feet. At that exact size, ask the manufacturer to confirm the applicable term rather than selecting the longer duration. Keep its answer with the actual glass specification and supplied warranty version.

Andersen's exclusions distinguish standard coverage from special glazing. Ask for the applicable document if your proposal includes impact glass, art glass, or another excluded option. A familiar product-line name does not override the selected glass package's coverage terms.

What a warranty repair would require at your opening

Marvin provides ten years of manufacturing-defect coverage for nonglass components under the 2026 PDF, while its remedy excludes the surrounding work described above. Ask the seller to describe who arranges service and who pays the costs outside that remedy.

The Andersen PDF separately excludes replacement labor, removal and disposal costs, and labor and materials for painting, staining, trim, or related carpentry. Its factory-authorized repair option should not be collapsed into a claim that all repairs always exclude labor; the specific remedy matters.

Have the installer supply a separate workmanship agreement. Ask how it addresses water entering around the opening, a field connection, or disturbed finishes. Record the service contact and the relationship between that agreement and the manufacturer coverage.

For a high window, ask how service access is arranged and priced. Request the accepted drawing, product labels, glass identification, purchase record, and complete warranty documents at handover. Those records help identify the affected component and the warranty remedy being requested.

Seattle's escape-opening rule still concerns operation

Seattle's 2021 Residential Code Chapter 3, R310.1, states: “Basements, habitable attics and every sleeping room shall have not less than one operable emergency escape and rescue opening.” Its exceptions include specified mechanical-only basements and qualifying sprinkler arrangements. R310.6 separately addresses alterations or repairs of existing basements and new sleeping rooms. A fixed circle or arch cannot itself supply the required operation. This statement applies the Seattle adopted provision; have the local reviewer determine which provisions apply to the room and alteration.

For an operating arch, use the manufacturer's actual net-clear-opening documentation and have the local reviewer assess it under the applicable provisions. The Marvin Ultimate Casement Round Top manual provides egress-and-vent-opening sections; the presence of those sections does not make every listed model an approved escape window.

Seattle's R310.2.2, Minimum dimensions, states: “The net clear opening dimensions shall be the result of normal operation of the opening.” Ask for the remaining clear passage with the sash and hardware in that position. Frame dimensions, glass area, and a decorative arch above an operating rectangle are different evidence. Operation alone does not establish compliance with the required dimensions or the separate minimum-area provision.

Resolve room use, ventilation, escape, and any proposed opening alteration before ordering. Elsewhere, obtain your jurisdiction's adopted requirements. Ask the contractor to identify what the project needs and which exact component supplies it; an attractive shape cannot answer those functional questions by itself.

What we could not verify

• A circle/oval product-detail PDF path returned 404. Dimensions above come from the reachable circle sizing sheet, and construction comes from the fetched full manufacturer guide.

Questions to ask before you compare quotes

• Does the rectangle comparison use equal glass area or equal outside dimensions?
• Which exact shape, radius, and frame dimensions are approved for fabrication?
• Is the shaped window fixed or an identified operating model?
• Who pays removal, installation, and finish restoration under the warranty?

Sources

All retrieved 2026-09-30.

1. TruePane Windows & Doors, "Custom Shape Windows in Columbus, OH" (direct visible-body fetch; regional installed estimates; no visible publication date)
2. Window Replacements of Frisco, "Specialty Shape Windows in Frisco, TX" (direct visible-body fetch; regional equal-area examples; no visible publication date)
3. Marvin, "Essential Collection Catalog," 2024 file, printed pages 26–27 (primary-document extraction; direct PDF fetch)
4. Marvin, "Introduction and Product Performance for Elevate/Essential," Prod Perf-16, version 2024.4 (primary-document extraction)
5. Andersen, "400 Series Product Guide for Professionals," specialty and joining pages (primary-document extraction; manufacturer CDN PDF linked from current product page)
6. Andersen, "Table of Sizes for Circle Windows," 2025–26 400 Series Product Guide (primary-document extraction)
7. Andersen, "400 Series Specialty Shape Windows" (operation and manufacturer PDF discovery)
8. Marvin, "Ultimate Casement Round Top Architectural Detail Manual," operating/stationary sections, version 2025.1 (primary-document extraction)
9. Marvin, "Window and Door Limited Warranty," effective January 12, 2026 (primary-document extraction)
10. Andersen, "400 Series/200 Series Windows & Doors Limited Warranty," revised September 8, 2023 (primary-document extraction)
11. Seattle SDCI, "2021 Seattle Residential Code, Chapter 3 — Building Planning," R310.1, R310.2.2 and R310.6 (primary-document extraction; direct PDF fetch)