Casement windows seal tighter and usually perform better on paper. Double-hung windows are cheaper, simpler, and go places casements cannot. That is the honest summary, and the right answer changes room by room in the same house.
The physical difference is the whole explanation. A casement cranks shut and the sash compresses into the frame against a continuous seal. A double-hung slides past a weatherstrip. Compression beats sliding for airtightness, and it always will.
Head to head
| Double-hung | Casement | |
|---|---|---|
| Seal type | Sliding weatherstrip | Compression |
| Typical air leakage | Slightly higher | Lowest of common styles |
| Cost, comparable quality | Baseline | 10–25% more |
| Cleaning the exterior | Both sashes tilt in | Ladder, above ground floor |
| Screen location | Outside | Inside |
| Opens over a walkway | Fine | Problem |
| Ventilation control | Top and bottom, stack effect | Full opening, scoops side breezes |
| Hardware to fail | Balances | Crank operator, hinges |
| Egress compliance | Needs a bigger opening | Easier in a small opening |
Where casements genuinely win
Airtightness and performance numbers. If you compare NFRC labels between a casement and a double-hung from the same manufacturer's same product line, the casement will typically show a lower air leakage figure and often a better U-factor. That is a design advantage, not a marketing claim.
Small openings that need to meet egress. The residential code requires most emergency escape and rescue openings in bedrooms to provide a minimum net clear opening of 5.7 square feet, with minimum dimensions and a sill height limit. A casement opens almost its entire frame; a double-hung gives you only the bottom sash. In a tight opening, that difference decides whether the window is legal.
Catching a side breeze. An open casement is a scoop. It redirects air moving parallel to the wall into the room, which a double-hung cannot do. In a house that relies on cross ventilation, this is a real and underrated advantage.
Wide, uninterrupted glass. No meeting rail across the middle of your view.
Where double-hungs win
Cost. Meaningfully cheaper for the same size and quality, and there is no crank mechanism to eventually replace.
Cleaning. Both sashes tilt in. Second-story windows get washed from inside the bedroom in ten minutes rather than from a ladder in an hour.
Anywhere something is outside the window. Walkways, patios, decks, narrow side yards, driveways. An outward-swinging sash over a path is a hazard, and some jurisdictions restrict it. This single practical constraint rules out casements on a lot of elevations.
Air conditioners and fans. A window unit goes in a double-hung. It does not go in a casement without a specialized kit.
Stack ventilation. Open the top sash and the bottom sash and warm air leaves at the top while cool air enters at the bottom. It is a genuinely effective free cooling trick on a mild evening, and casements cannot do it.
Traditional appearance. On an older home, casements in every opening can look wrong in a way that is hard to unsee.
The hardware question nobody asks
Casement operators are mechanical assemblies. They work beautifully and then, somewhere around year ten to fifteen, one of them starts grinding, and you find out whether the manufacturer still stocks that operator. On an obscure or discontinued line, they often do not, and you are into universal replacements and a bit of improvisation.
Double-hung balances are simpler, more standardized, and cheaper to replace. Roughly $30 for a part and twenty minutes.
Neither is a reason to choose one over the other. It is a reason to buy from a manufacturer that will still exist in fifteen years, whichever style you pick.
Our actual recommendation, room by room
Bedrooms: casement, if the opening is small enough that egress compliance is tight. Otherwise either.
Anything over a walkway, patio, or driveway: double-hung, no discussion.
Kitchen over the sink: casement. The crank is reachable across a counter; a double-hung sash requires leaning over the sink and shoving.
Second floor, anywhere you will resent a ladder: double-hung, for cleaning alone.
Rooms that need cross ventilation: casement, angled to catch the prevailing breeze.
Bathrooms: either, but pick obscure glass and remember that casement screens live inside where they collect steam.
A whole traditional facade: double-hung, for appearance, and spend the money you save on better glass.
The opinion, since "both are good" helps nobody
If you are replacing windows in a mixed house and want one decision: buy quality double-hungs everywhere except the kitchen sink and any tight bedroom egress opening, and put the savings into a better low-E package.
The performance gap between a good double-hung and a good casement is smaller than the gap between a cheap window and a good one. Frame quality, glass coating, and installation matter more than the operating style. Choosing casements throughout and then economizing on the glass to afford them is backwards, and it is a trade people make constantly.
What actually matters more than either: the NFRC numbers on the label and whether the installer flashes the sill properly. Our energy-efficient windows guide covers reading those labels, and our repair versus replace guide covers whether you need new windows in the first place.
Des Moines Window Pros installs double-hung windows, casements, and vinyl replacement units across Des Moines and Greater Des Moines, and we will happily walk the house and tell you which openings genuinely want which style. Most homes end up with a mix, and that is the right answer.
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Related services in Des Moines
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- High-Performance Glazing and Energy-Efficient Windows →
Before we quote glass we ask what the attic measures. The Department of Energy puts heat gain and heat loss through windows at 25 to 30 percent of residential heating and cooling energy use, which leaves roughly three quarters of the problem somewhere else in the house.
- Vinyl Replacement Windows →
Vinyl is where most of the value sits in this market, and we will argue that against anyone who wants three times the money for a frame you cannot see from the street. What decides a vinyl window is the extrusion and the installation, not the badge on the corner.
- Double-Hung and Single-Hung Windows →
The double-hung is the most common window in this city and by far the most over-replaced. Half the calls we take about them concern a sash that drops when you let go of it, and that symptom points at the balance rather than at the window around it.
- Fiberglass and Composite Window Frames →
Fiberglass earns its premium in a narrow set of cases, and we would rather name those cases than sell the material by default. Pultruded frames cost meaningfully more than vinyl per opening, so the only question worth asking is whether your particular openings repay the difference.
- Aluminum-Clad Wood Windows and Sash Restoration →
This city has a lot of houses worth keeping original sash in. The 2019-2023 American Community Survey puts about 27,000 of Des Moines' roughly 97,000 housing units at 1939 or earlier, and much of that glass is old-growth wood that outlasts what replaced it.
Frequently asked questions
Which is better, double-hung or casement?
Casements seal tighter and usually post better air leakage and U-factor numbers, because the sash compresses against the frame when you crank it shut. Double-hungs slide past a weatherstrip instead. If airtightness is the priority, casement wins. If cost, simplicity, and screen placement matter more, double-hung wins.
Are casement windows more expensive?
Typically 10 to 25 percent more for a comparable size and quality, mostly because of the operating hardware. The crank mechanism and hinges are also the parts most likely to need service in year twelve, which is worth factoring into the comparison.
Can casement windows be used anywhere?
No, and this catches people out. A casement swings outward, so it should not open over a walkway, patio, deck path, or driveway where someone can walk into it. Some jurisdictions restrict it outright. Double-hungs and sliders have no such problem.
Which window style is better for egress?
Casement, usually. The residential code requires a minimum net clear opening of 5.7 square feet for most emergency escape windows, and a casement gives you nearly the whole opening when cranked fully open. A double-hung gives you only the bottom half, so it needs to be physically larger to comply.
Do double-hung windows leak more air?
As a category they test slightly higher on air leakage than casements, because a sliding seal cannot compress the way a crank-closed sash does. A well-made modern double-hung is still very tight — a cheap casement will lose to a good double-hung every time.
Which is easier to clean?
Double-hung, clearly. Both sashes tilt inward so you can wash the exterior glass from inside the room. Cleaning the outside of a casement above the ground floor generally means a ladder or a long-handled squeegee and some optimism.
Local context
How this applies in Des Moines, IA
Every article here is written from window work done in Des Moines and Greater Des Moines, so the numbers reflect local labour, permit and material costs rather than a national average. Your own job can land either side of them depending on access, the condition of what is already there, and the materials you pick — dense-pack cellulose and attic top-plate air sealing done ahead of glass, AERC-rated low-e interior and exterior storm panels, warm-edge spacers in replacement insulated glass units.
The way to turn any of this into a real answer is to have someone look at your actual situation. The free estimate is free, itemized and written down, with no deposit and no obligation. Call (844) 511-2320 or start on the Des Moines Window Pros homepage.
Areas Des Moines Window Pros covers
Des Moines first, then the surrounding communities of Greater Des Moines. Each has its own page with local detail rather than a copy of this one:
- West Des Moines, IA — Polk County, population 68,723 at the 2020 census
- Ankeny, IA — Polk County, population 67,887 at the 2020 census
- Ames, IA — Story County, population 66,427 at the 2020 census
- Urbandale, IA — Polk County, population 45,580 at the 2020 census
- Johnston, IA — Polk County, population 24,064 at the 2020 census
- Waukee, IA — Dallas County, population 23,940 at the 2020 census
Or jump to the full list of Des Moines services.
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The Des Moines Window Pros Team
Licensed window pros in Des Moines, IA
Written by the Des Moines Window Pros team — licensed, insured window pros serving Des Moines, IA and the surrounding area.