Last reviewed October 31, 2026.
The window over the kitchen sink only opens if you lean past the faucet and shove with both arms, and by August it sticks halfway. The installer suggests a casement there, a crank you turn with one hand. Then comes the harder question: should the bedrooms change too?
How each style opens and seals
A double-hung window has two sashes that slide past each other in side tracks. A casement hangs on a hinge along one side and cranks outward. When it closes, the sash pulls in tight against the frame.
That squeeze is why casements tend to shut tighter. A January 2004 retrofit guide written by Oak Ridge National Laboratory for the Department of Energy says windows that compress a gasket, rather than relying on a sliding seal, will typically let less air leak in and out, and it suggested homeowners consider casements even where the old windows were hung. Andersen’s guide to window styles calls the casement “the most energy-efficient operable window.”
The price of that swing is space outside. Andersen points out that an outward-swinging casement can take room away from patios, decks and walkways in a way that double-hung, single-hung and gliding windows do not.
The air leakage line on the NFRC label
Every new window comes with a National Fenestration Rating Council label. NFRC describes its Air Leakage entry as a measure of how much air will enter a room through the product, and gives its range as 0.3 or less.
ENERGY STAR’s Version 7.0 criteria, in effect since October 23, 2023, require windows to have an air leakage rating no higher than 0.3 cubic feet per minute per square foot, shown as ”≤ 0.3” on the temporary NFRC label or proven with an accepted certification label such as the AAMA Gold Label. The spec names ASTM E283 as the air leakage test.
The catch is that ”≤ 0.3” is a ceiling, not the tested result. Two windows can both pass and still differ. We did not find a Long Island installer or a manufacturer page that publishes tested air leakage figures for a matching casement and double-hung, so ask the installer for the test results on each product you are quoted.
Cleaning the outside glass from indoors
Neither style should send you up a ladder. Andersen says its double-hung windows have a tilt-wash feature, so the sashes tip inward and you clean the exterior glass from inside. It describes its casements the same way, easy to clean on the outside from inside the home.
That counts most on a second floor or in a dormer. Not every product line has these features, so check the exact model on the quote.
Bedroom escape openings and the replacement rule
The Department of State’s final draft of the 2025 Residential Code (July 2024) calls for an emergency escape and rescue opening in every sleeping room, in basements and in habitable attics, with a few exceptions such as a small basement used only for mechanical equipment. The same draft sets the minimums:
| Requirement | Minimum |
|---|---|
| Net clear opening | 5.7 sq ft, or 5 sq ft at a grade floor |
| Clear height | 24 inches |
| Clear width | 20 inches |
| Sill height | no more than 44 inches above the floor |
A double-hung opens one sash at a time, so only part of the window’s height is ever clear. A casement swings fully out of the way, and Andersen notes its top-to-bottom opening and says its casement sizes can meet egress requirements.
For replacements, the 2025 Existing Building Code of New York State, part of the 2025 Uniform Code that the Department of State says took effect December 31, 2025, has a specific exemption. A replacement window does not have to meet the full size rules if it is the manufacturer’s largest standard size that fits the existing frame or rough opening, and it may be the same operating style or a style with equal or greater opening area. Swapping a double-hung for a casement in the same opening fits that rule. Going the other way, casement to double-hung, can shrink the clear opening, so call your building department before you order. Basement egress windows cut into a foundation are a separate job, priced on the window replacement cost page.
The price gap between the two
All American Home Improvement’s undated Long Island cost page puts a double-hung at $450 to $1,250 installed and a casement at $525 to $1,500. Installation alone runs $150 to $350 for a double-hung and $175 to $400 for a casement in the same breakdown.
Long Island Windows and Siding (October 2025) lists a vinyl double-hung at $700 to $1,150 and a fiberglass casement at $1,000 to $1,600, but those two rows are different frame materials, so that gap mixes style and material. Neither company explains why casements cost more. Frame material moves the price too, which the frame materials guide covers.
Choosing room by room
Plenty of houses end up with a mix. The sources point to a few patterns:
- Beside a deck, porch or walkway, a double-hung keeps the sash out of the path.
- In a bedroom with a small opening, a casement usually gives more clear area for escape.
- On a Colonial front, Royal Windows and Doors (March 2026) says double-hung windows suit the look, unlike casements that swing outward.
If looks matter to you, keep one style on each face of the house. Either way, have the installer list the style for every opening on the quote. Our window replacement page covers insert versus full-frame and what else to compare.
