The Style Choice People Underestimate
Brand and material get the research hours, but the operating style — crank-out casement versus slide-up double-hung — changes how a window seals, vents, cleans, and passes bedroom egress code. After 46 years of installing both across the Treasure Valley, we can make the trade-offs concrete.
Where Casements Win
Air-tightness, by design. The sash presses into compression weatherstripping all the way around, and wind load presses it harder. On Canyon County open ground, Kuna gusts, and foothills exposure, windward-wall casements are our standing recommendation — the whistle-in-January problem is largely a sliding-seal problem.
Egress math. A casement swings its entire area open. Idaho bedrooms need 5.7 square feet of clear opening (the egress rules), and a double-hung only offers half its glass area — so in tight openings, a casement often passes code where a double-hung physically can't. Basement bedrooms live and die on this.
Awkward reaches. Over the kitchen sink, behind the tub: a crank handle beats hauling up a sash you can barely touch.
Where Double-Hungs Win
The architecture. Craftsman, farmhouse, colonial, most traditional Boise housing — double-hungs are the correct vocabulary, and casements on a North End facade read wrong (design review will agree).
Ventilation control. Open the top sash for exhaust and the bottom for intake and a double-hung ventilates a room a single casement can't match, screens staying put throughout.
Simplicity in the elements. No crank mechanism to wear, no sash cantilevered into weather during a surprise thunderstorm, tilt-in cleaning from inside — a practical package that explains the style's two-century run.
Our Room-by-Room Answer Key
Windward and west walls: casement. Bedrooms with marginal opening sizes: casement (egress). Over counters and tubs: casement. Street-facing traditional elevations: double-hung. Kids' rooms and rentals: double-hung (no crank casualties). Everything else: whichever the house's character votes for — and the mixed answer is the usual winner.
Style is free to get right at the measure and expensive to regret after: (208) 376-2200 for the walk-through.
Frequently Asked Questions
Which seals better, casement or double-hung?
Casements, measurably. A casement cranks shut against compression weatherstripping — and wind pushing on it seals it tighter — while a double-hung's sashes slide past brush seals that must stay loose enough to move. On air-infiltration numbers, casements typically test several times tighter. On windy Idaho exposures that's a real-world difference you can hear in January.
Why does anyone choose double-hung then?
Tradition, ventilation control, and toughness around screens and window AC units. Double-hungs are the correct look on most classic American architecture, their two-sash design vents top-and-bottom simultaneously, tilt-in sashes clean from indoors, and there's no crank hardware for kids to hang on. They're also friendlier to openings onto walkways and decks, where a cranked-out casement sash intrudes.
Is there a price difference between the styles?
Modest — casements typically run 10–20% more than a same-size double-hung in the same product line, mostly hardware cost. Style choice moves your budget far less than material and brand choices do.
Can I mix casements and double-hungs on one house?
Houses do it constantly and well: double-hungs across the traditional front, casements on the windy west wall and over the kitchen sink (cranks beat wrestling a sash across a counter). Matching frame color and glass keeps the mix coherent.
Sources & Testing Data
Last reviewed 2026-07-05 by Wood Windows Inc — (208) 376-2200