Double-Hung vs Casement Windows: Sliding Sash vs Crank-Out Ventilation
One slides vertically on a track, the other cranks outward on a hinge. That single mechanical difference changes sealing, airflow, and where each fits best.
Updated August 2026
Who wins what
Owners prioritizing draft reduction in a cold or windy climate.
Basis: Casement sashes compress against the frame with the crank mechanism, and manufacturers commonly publish lower certified air-infiltration ratings for casement lines than for comparable double-hung lines.
Rooms that need the largest possible open-air share of the window.
Basis: A casement sash typically swings open to nearly its full frame area, while a double-hung sash opens only as far as it slides, commonly capped near half the total window area.
Windows located over a walkway, deck, or low landscaping where an outward-swinging sash is impractical.
Basis: Double-hung sashes stay within the frame plane; casement sashes swing outward from the frame when open, per manufacturer operating design.
Key differences at a glance
Operation
Even- Double-hung windows
- Vertical slide on a spring or block-and-tackle balance
- Casement windows
- Crank-out hinge on one side of the sash
Air-sealing design
Casement windows- Double-hung windows
- Compression against a track and jamb weatherstrip
- Casement windows
- Compression seal tightened by the crank mechanism, commonly rated tighter
Ventilation opening
Casement windows- Double-hung windows
- Opens to roughly half the frame area at most
- Casement windows
- Can open to nearly the full frame area
Outward projection when open
Double-hung windows- Double-hung windows
- None; sash stays in the frame plane
- Casement windows
- Projects outward from the wall when open
Screen placement
Even- Double-hung windows
- Screen mounts on the exterior side of the frame
- Casement windows
- Screen mounts on the interior side since the sash swings out
Hardware complexity
Even- Double-hung windows
- Balance system with springs or weights
- Casement windows
- Crank gear mechanism and hinge hardware
Full scorecard
| Metric | Double-hung windows | Casement windows | Edge |
|---|---|---|---|
| VentilationManufacturer operating specifications comparing opening area by window type | Opens to roughly half the frame area | Opens to nearly the full frame area | Casement windows |
| Egress suitabilityEgress bedroom windows are governed by the International Residential Code as adopted and amended locally, which sets minimum opening area, width, height, and sill height for emergency escape. Requirements vary by jurisdiction and by whether the room is a new build or existing construction, so confirm the exact figures with your local building department before ordering a bedroom window. | Clear opening depends on how far the sash slides at the specific size ordered | Clear opening depends on the crank's swing angle and the specific size ordered | Even |
| Air-sealing potentialManufacturer NFRC-tested air-infiltration ratings by window type | Track-and-jamb weatherstrip seal | Compression seal tightened by the crank, commonly published with a lower air-infiltration rating | Casement windows |
| Cleaning accessManufacturer product documentation on cleaning access by window type | Sashes commonly tilt in for interior cleaning | Sash swings fully open, giving direct access to both sides from inside | Even |
| Cost positioningManufacturer price sheets and contractor quote patterns | Moderate cost at a given size and glass package | Comparable to moderately higher cost than double-hung at a matched size, driven by the crank hardware | Double-hung windows |
Which one is right for you?
Choose Double-hung windows if…
- The window sits over a walkway, patio, or low shrub bed where an outward-swinging sash would be impractical.
- You want a traditional double-sash appearance that matches an existing home style.
- You prefer tilt-in interior cleaning without an outward-projecting sash.
Choose Casement windows if…
- Air-sealing performance in a cold or windy climate is a priority.
- You want the largest possible ventilation opening in a narrower window, such as beside a fixed picture window.
- The window is above a countertop or other obstruction where reaching a sliding sash's upper track would be awkward.
Choose neither if…
- You want the widest unobstructed view with no operable ventilation need; a fixed picture window may fit better than either operable style.
- The wall is a busy walkway on the exterior side and cranking the sash open would create a hazard; consider an awning window instead.
The short answer
Double-hung and casement windows differ mainly in how the sash moves: vertical slide versus outward crank. Casement generally seals tighter and opens wider; double-hung stays flush with the wall and avoids outward projection. Choose based on climate, exterior clearance, and how much open ventilation area the room needs.
Cost breakdown
| Line item | Double-hung windows | Casement windows |
|---|---|---|
| Unit price, matched frame size and glass package | Moderate | Comparable to moderately higher, reflecting crank hardware |
| Installation labor | Standard retrofit labor | Standard retrofit labor; hinge alignment adds minor time |
| Screen replacement over time | Exterior-mounted screen, common wear item | Interior-mounted screen, common wear item |
Assumes a standard vinyl or fiberglass replacement window in a comparable size and glass package installed as a retrofit. Crank hardware and multi-point locking on casement lines can push cost above double-hung at the same size; confirm with a written contractor quote.
Long-term value
Casement's compression seal tends to hold its air-sealing performance well over time as long as the crank hardware is maintained, since the sash continues to press into the frame with each closing. Double-hung's balance hardware can loosen over years of use, occasionally requiring spring or channel adjustment. Both are commonly specified across a 20-plus year service life; neither has an independently published lifespan advantage over the other.
Decision framework
Compression seal design commonly rates tighter for air infiltration than a sliding sash.
Sash stays within the frame plane and does not project into the space below.
Opens to nearly its full frame area, maximizing ventilation in a limited width.
Preserves the visual proportion of the original window style.
- Installing a casement window where the outward swing will hit a walkway, deck rail, or air conditioning unit.
- Assuming casement is always more expensive; pricing depends on the specific product line and hardware tier, not the style alone.
- Overlooking that a casement's crank arm and gear can wear over decades and may need periodic hardware replacement.
- Ignoring screen placement differences: casement screens sit inside the home, which some owners find less convenient to remove for cleaning.
- Choosing a hung window in a narrow opening where a casement would have provided meaningfully more ventilation area.
Tools and next steps
Frequently compared next
Frequently asked questions
Which window type seals better against drafts?
Casement windows generally publish tighter certified air-infiltration ratings because the crank mechanism compresses the sash into the frame. Compare the NFRC rating on the specific models you are considering rather than assuming by style alone.
Can a casement window meet bedroom egress requirements?
It can, depending on the specific unit's swing angle and clear opening dimensions relative to your locally adopted code. Confirm the NFRC-listed clear opening against your building department's current requirement.
Do casement windows cost more than double-hung?
Often somewhat more at a matched size, largely due to the crank gear and multi-point locking hardware, though pricing varies by manufacturer and product tier. Compare written quotes at the same glass package.
Is a casement window a problem near a walkway?
It can be, since the sash swings outward when open. Consider a double-hung or awning window in locations where an outward-swinging sash would obstruct foot traffic.
Which is easier to clean?
Both are commonly designed for interior cleaning: double-hung sashes tilt in, and casement sashes swing fully open. Neither has a clear documented advantage; check the specific product's cleaning design.
Do both window types come with the same screen options?
Screen placement differs: casement screens are typically mounted on the interior side since the sash swings outward, while double-hung screens mount on the exterior side. Confirm screen type when ordering.
Verify these details yourself
- Exact air-infiltration rating differences between specific product lines you are considering; check the NFRC label on each model.
- Long-term crank hardware failure rates, since no independent public dataset was found.
- Whether your specific opening meets your locally adopted egress requirement; confirm with your building department.
Methodology and sources
Specifications, pricing, warranties, and availability may change. We verify key details against official or reputable public sources and note where information is estimated or not publicly disclosed. HomeownerAnswers does not perform product testing.
- NFRC certified product directory - Independent testing, checked 2026-08-03, confidence: high
- ENERGY STAR windows, doors, and skylights program - Government, checked 2026-08-03, confidence: high
- International Residential Code egress provisions - Regulatory filing, checked 2026-08-03, confidence: medium. Adopted and amended by state and local jurisdiction; verify the current locally enforced version.
- Manufacturer product documentation for casement and double-hung windows - Official manufacturer, checked 2026-08-03, confidence: medium
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