Custom-Shape Window Types: Arches, Rounds, Octagons and Angles
Arched and Round-Top Windows
An arched window has a square bottom and a curved top, and it is usually fixed glass set above another window or a door. Cost guides price arched units well above a rectangle of the same size: in one guide's fiberglass prices, a stock arch runs $300 to $1,100 for the window alone and a custom one $390 to $2,200. Ask whether the quote is for a fixed unit or an operating sash with an arched head.
Half-Rounds and Eyebrows
Half-rounds (a full semicircle cut in two) and eyebrows (a shallow, wide arc) are among the arched shapes window makers list. Both are often paired with a rectangular window or a door below. Because the curve has to match the opening exactly, guides warn that specialty shapes may need precise measurements or custom framing. If the old trim is curved, ask whether it comes out and is rebuilt or stays in place.
Octagon and Circle Windows
Octagons, circles, ovals, hexagons and quarter circles show up in makers' specialty lines. They are still custom orders, and one guide starts custom windows at around $1,000. Labor can run up to $1,200 for odd-shaped units, compared with $100 to $800 for a standard window. On a stair landing or an attic gable, ask how the crew will reach it and whether staging is in the price.
Trapezoid and Gable-End Windows
Trapezoids and other angled-top windows sit in makers' specialty ranges alongside arches. Each one is built to the angles of its opening, so the measurements carry the job: a wrong angle can mean a remade unit and a second wait. For square fixed glass above a door or window, see transom windows instead.
Why Lowell homeowners call Lowell Window Replacement
- One independent window contractor gets your request
- Ask for the HIC number: MA contracts must show it
- Written contract on any job over $1,000
- The call and the referral are free
Custom-Shape Window Cost and Lead Time
Any window that departs from a standard design costs more, because it is built to order. What moves the number:
Survey average
about $580 per specialty window before installation.Stock vs custom
a custom fiberglass arch tops out at $2,200 for the window alone, double the stock arch's $1,100.Labor
up to $1,200 per odd-shaped or oversized unit.Build time
6 to 12 weeks once the design is signed off; 16 to 20 weeks for complex designs or specialty materials.Whole project
8 to 16 weeks from first consultation to install, with 1 to 5 days on site, in one installer's guide.
Cost guides agree custom building drives up material cost, and one notes that non-standard openings are common in older homes.
Custom-Shape Windows on Older Lowell Houses
Openings in an older Lowell house are rarely the size the drawings say. Three things to settle before an order goes in:
Historic district
Exterior changes in some districts need Historic Board review first, and a new window shape is an exterior change.Size changes
Enlarging or reshaping an opening is framing work; check the building permit before the wall is opened.Warranty terms
Guides advise checking for warranty exclusions on specialty shapes and custom orders; get the terms in writing.
A good installer will measure the opening on site before ordering, even if you have measurements of your own.