· by Michael Blair, Nashville's Windows & Doors
Most replacement window quotes in Nashville default to double-hung, because that is what the house already has and it is what the neighbors have. It is a fine window. But a casement, which is hinged at the side and cranks outward, seals differently, vents differently and suits some openings much better, and a house can mix the two without looking odd. The choice is worth making room by room rather than once for the whole order.
How each one seals
A double-hung window has two sashes that slide past each other in a track, so it seals with weatherstripping brushed against a moving surface. That is a compromise by design: it has to slide, so it cannot clamp. A casement closes like a door against a compression gasket and the crank pulls it tight, which is why casements consistently test tighter against air leakage than double-hungs of the same quality.
In practice, on a windy winter night the difference is felt. A casement on the north wall of a Nashville house is noticeably less drafty than a double-hung in the same opening. Over a whole house of windows it shows up in the heating bill, though the effect is smaller than the glass itself.
Ventilation, rain and the direction of the wind
A casement opens its whole area and, opened into the prevailing breeze, scoops air into the room. A double-hung opens at most half its area. For a bedroom you want to ventilate on a spring evening, the casement wins clearly. Opened into a storm, though, a casement takes the rain straight in, and an open casement in a summer thunderstorm gets the sash wet and stresses the hinges; a double-hung open a few inches at the top sheds most rain.
Casements also swing outward into whatever is there: a walkway, a deck, a shrub. On a ground floor next to a path they are a hazard at head height, and screens on casements sit inside the glass, which some people dislike.
- Bedrooms and living rooms on the breeze side: casement vents better
- Openings over a walkway or deck: double-hung or awning
- Over a kitchen sink or behind a counter: casement, because the crank is reachable
- Historic or traditional facade: double-hung matches the street
Cleaning, screens and the long term
A good double-hung tilts both sashes inward so the outside glass is cleaned from the room, which on a second story is the whole reason to want one. A casement cranked fully open can usually be reached around from inside on smaller sizes but not on large ones. Both have parts that wear: double-hung balances and tilt latches, casement crank operators and hinges. Neither is hard to replace, but the crank hardware is the more expensive piece.
In humidity, the concern with casements is a sash that swells or a gasket that takes a set, so the window no longer pulls tight. Good hardware and a quality frame material prevent it. Vinyl double-hungs in cheap frames have their own problem here: the sashes warp in sun on a west wall and stop meeting at the check rail.
What the house looks like
Double-hung windows are the vocabulary of most Nashville housing, from the pre-war four-squares to the 1990s subdivisions, and on the front of a traditional house they are usually the right choice for the facade, especially with grilles. Casements on the front of a colonial read as a mistake. On a ranch, a mid-century house or anything contemporary, casements or a mix of fixed and casement units suit the look and give bigger uninterrupted glass.
Mixing is normal: double-hungs across the front, casements on the sides and back where ventilation and sealing matter and nobody is judging the elevation. The frame color, the glass and the grille pattern should match across both so the house reads as one order, not two.