Casement Windows: How They Work, Downsides and What They Cost

A casement window is a single sash hinged on one side that swings outward like a door, usually opened with a crank ¹. When it closes, the locking hardware pulls the sash tight into the frame, and Andersen describes casements as among its most energy-efficient windows, saying the seal even tightens when wind presses on it ¹. Casements are popular over kitchen sinks and in modern homes, and they can also be built to look like a double-hung window ^{1 2}.

The main downsides are the outward swing, which needs clear space outside, and the crank and hinge hardware, which is more to maintain than a sliding sash ^{2 4}. On price, a typical range reported by Angi in October 2026 is $260 to $950 per window replaced, with a national average of $815 ⁴; other surveys report wider ranges, set out below.

How a casement window works

A casement has one sash in one frame, hinged along a side ¹. Turning the crank swings the sash out, and because it opens along its full height it can bring in air from top to bottom ³. Some of Andersen's casements use hinges that let the sash open to 95 degrees, and its largest casement is 8 feet tall ³. Two casements can be joined without wall framing between them (a twin casement), and a pair hinged on the outer edges with no center post is called a French or push-out casement ³.

Andersen attributes the efficiency to the design and the seal: with a single sash there are fewer openings for air leakage, and the hardware pulls the sash into the frame when it locks ^{1 3}. Picture windows, which do not open, are the only type Andersen ranks higher ¹.

Hardware, screens and cleaning

Casement hardware is the crank, the hinges and a lock, and it comes in a range of finishes; some lines offer power operation ³. Andersen says insect screens can be ordered with all of its casements ³. Cleaning is done from inside: with the sash fully open there is enough room between the sash and the frame to reach the outside of the glass, which helps on an upper floor ¹.

Clearance outside

The open sash projects outside the wall. Andersen advises against a casement next to a walkway, porch or deck where it could become an obstacle, and suggests a sliding or hung window there instead because those open flush with the wall ². The same check applies to shrubs, gutters and anything mounted on the siding near the window.

Downsides of casement windows

• Space outside. The open sash needs clear room, as above ².
• More hardware. Angi notes that casements, with their many moving parts, may need repairs more often than simpler windows, and puts common hardware repairs at $75 to $200 ⁴.
• Security. HomeGuide notes that a casement relies on its hinges and lock, which can wear over time, and that large egress casements are big enough for a person to climb through ⁸.
• Price. Surveys put casements above single-hung and double-hung windows of similar size; Fixr says the difference is a few hundred dollars per window ⁵.

Casement vs. double-hung

The two differ in how they open, not in what they are made of. A double-hung has two sashes that slide up and down inside the frame and stays flush with the wall; a casement has one sash that swings out ^{1 2}. Choose a casement where you have to reach over a counter to open the window, where you want a single sash that seals against the frame, or where you want an unbroken pane of glass. Choose a double-hung next to a walkway or deck, in a traditional house where the look matters, or where a crank would be out of character ². Andersen makes casements that imitate the look of a double-hung, so the style question can sometimes be separated from the opening question ¹.

On price, HomeAdvisor's June 17, 2026 window-unit table, which excludes labor, lists casements at $150 to $1,000 and double-hung windows at $150 to $650 ⁷. HomeGuide's February 5, 2026 installed figures are $400 to $3,000 for a casement and $350 to $2,500 for a double-hung ⁶. More on the other window types is in types of windows, and on double-hung prices in double-hung window cost.

What casement windows cost

Four cost surveys report casement prices, and they do not agree. Each uses its own method and date, and some figures include labor while others do not.

Why they differ: HomeAdvisor's casement row is the window alone, so it sits lowest ⁷. HomeGuide's type table covers everything from small units to large ones and says installed prices vary with the installer ⁶. Angi says it researches project costs using Bureau of Labor Statistics data, academic journals, market studies and expert interviews, and says installation adds $100 to $300 per window to its range ⁴; Fixr says it uses pricing databases, contractors and industry experts ⁵; HomeAdvisor says it surveys customers after a project and adds similar research ⁷; HomeGuide says its data comes from research and project costs reported by its members ⁶.

What moves the price

• Size. Fixr's table for vinyl, double-pane casements runs from $290 to $480 installed for a 24 by 36 inch window up to $720 to $1,200 for 36 by 60 inches ⁵.
• Configuration. Fixr reports $225 to $550 for a single-frame casement, $450 to $950 for a double-frame (French) casement, and $600 to $1,300 for a picture window with casement flankers ⁵.
• Frame material. Fixr's installed ranges run from $300 to $1,000 for vinyl to $700 to $2,000 for fiberglass ⁵.
• Labor and removal. Angi puts installation at $100 to $300 per window plus about $60 to remove and dispose of the old one ⁴. Fixr puts labor at 20% to 40% of the total ⁵.
• Opening changes. Angi reports $800 to $5,000 to enlarge an opening and $1,000 to $5,000 to cut a new one ⁴.

Permits

Whether a casement job needs a permit depends on what is changed and on your local building department. The model residential code, IRC Section R105.1, requires a permit before a building is enlarged or altered, and its list of exempt work in R105.2 does not list window replacement; each city or county adopts and amends its own version ⁹. Angi notes that a like-for-like replacement may not need a permit while enlarging or cutting an opening likely will, and puts a window permit at about $50 ⁴. Ask the installer who pulls the permit and whether it is in the quote.

Before you get quotes

Count the casements, measure each one, and note which way each opens (hinged on the left or the right as seen from outside). Ask each installer to quote the same frame material, glass package and installation method, so the prices compare line by line. How to choose a window installer covers what a written quote should list, and window replacement cost covers the rest of the house. When you are ready, you can compare quotes from window installers.

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About these figures

• ¹ Reported: Andersen's description of how a casement opens, seals, cleans and compares with other types, checked October 22, 2026.
• ² Reported: Andersen's placement advice for casements near walkways, porches and decks, checked October 22, 2026.
• ³ Reported: Andersen's casement product information (95-degree hinges, 8-foot height, screens, hardware, twin and French casements), checked October 22, 2026.
• ⁴ Reported: Angi's casement replacement range of $260 to $950 and $815 average, labor, removal, repair, opening and permit figures, updated October 20, 2026, checked October 22, 2026.
• ⁵ Reported: Fixr's casement ranges by size, configuration and frame material, labor share and its price comparison with other types, updated January 30, 2026, checked October 22, 2026.
• ⁶ Reported: HomeGuide's installed ranges for casement and double-hung windows from its window replacement guide dated February 5, 2026, checked October 22, 2026.
• ⁷ Reported: HomeAdvisor's window-unit price ranges for casement and double-hung windows, updated June 17, 2026, checked October 22, 2026.
• ⁸ Reported: HomeGuide's note on casement security from its casement guide dated August 3, 2023, checked October 22, 2026.
• ⁹ Official record: International Residential Code 2021, Sections R105.1 and R105.2, on when a permit is needed, checked October 22, 2026.