Is it strange to mix double hung and casement windows on front elevation? Trying to find pictures online but couldn't find anything that could help make this decision. Part of our elevation has the windows from the garage that we know we will not open/use them at all but since they are facing the front, our architect has suggested using casement windows for the look. We are thinking may be we can use double-hung on those and casement for the rest of the windows on the front due to the cost difference. Do casement window really make a big difference on the overall appearance?

Next big question we have is whether to have grid or not on the glass and would love to hear about everyone's experiences. We've also seen windows with grid on top but clear at the bottom. This may be a silly question to ask but we haven't gotten any quote yet, do windows with more grids generally cost more?

Grids between glass is not a significant upcharge. I feel like it is $10 a window. SDLs are more expensive and look much nicer.

Fixed windows with some manufacturers are significantly cheaper than casement. So strangely double hungs are cheaper than fixed often enough. Since you are talking garage, you aren't really worried about infiltration.

Downsides of casement
- screen is inside - can't do solar blocking screens, sometimes bugs get in there and die
- cranking mechanism does break
- cost
- can't just open top half for toddler safety
- harder to install security sensor
- if open during rain, the top gets wet
- a double hung with a overhang can be more open with less concern for water coming in house when raining

Pros - double the ventilation, often easier to open

We have a mixed elevation and I didn't even realize it....

I forgot to reinforce the pro of air infiltration.

All casements have vertical lights. So do our double hungs. I think it looks great and intentional. I do not like when there are horizontal casements mixed with vertical double hungs. . . .

The french doors are more vertical than they look in this picture. Wish I had a better picture . . .

We will probably be using a mix of DH and casement windows on our front elevation, with non-operable windows for garage to save cost?! Now my dilemma is whether casement windows will make such a big impact on the overall look. We are going for a cleaner look, modern european style, using mainly bricks with stone accents on the front. It seems like DH is more suitable for homes with traditional or Georgian look. I am still having a hard time deciding whether we should spend extra on casement windows on the front or keep everything DH, and may still get a similar effect on the look in the end. Afterall, the main difference between the two windows apart from how it's operated is that extra bar that I see on DH...and that's costing us more just to get casement windows for a relatively cleaner look. I am torn! Decision, decision!

They are more energy efficient as they seal up very tight for the winter.

They open up the full window as opposed to just half the window with DH.

They are easier to open, especially on windows over sinks and counters where the position and upper body strength to open a DH is just too awkward.

The best part is they act like fins on the house when they are open and capture every passing breeze which keeps the house comfortable, even in very hot weather.

The other main difference is the energy efficiency; decreased air infiltration is a big pro of casement windows. And if you are doing clean, modern European, you can forgo the grids to save money. Grids aren't seen as much in European windows.

DH 48x72 - .10 CFM at at 25 mph
Casement 36x72 - .09 CFM at 25 mph

Straight from the spec sheet. Per sqft, DH was actually better. Now this may not be the best way to measure air infiltration but there it is. Not all windows may match this but it just shows that casement is not necessarily always better (and if it is, is the difference significant?)

Are some window designs better than others for air infiltration?
Yes. Casement and awning windows offer excellent air infiltration performance because pressure from the wind tightens up the seals. Tilt-and-turn windows, with their dual compression seals and multiple locking points around the perimeter offer equal or better performance. Traditional double-hung windows (sometimes called "vertical sliders") cannot do as well due to their sliding surfaces where compression seals are not possible. And, horizontal sliders generally have the worst air infiltration performance of all window types. Beyond the sliding surfaces of the double hung, these windows have frames designed for sash removal. This feature, along with necessary provisions for drainage, make it impossible to seal these windows as tightly as a double hung, much less a casement."
ANSWERED BY MARTIN HOLLADAY, GBA ADVISOR
Posted Mon, 09/21/2009 - 10:07

Firstly a double hung window is not as air tight as a casement window. The double hung window has to slide, so its weatherstripping can't be as tight as a casement or it won't slide. That's obvious to most people.

What is not so obvious is that sliding windows aren't as air tight as casements because the weatherstripping changes plane. Think of the bottom sash of a double hung. The bottom and side rails are weatherstripped along the edge of the rail. But what about the meeting rail? It's weatherstripped along the outer face. It is difficult, very difficult, to maintain the integrity of the air seal through this change of plane.

Despite the fact that double hung windows are inherently draftier than casements, this does not have a major effect on your annual heating bill. The reality is that as long as new windows can maintain their tested air tightness (this topic will be the subject of a future column) very little of the window's heat loss is due to air leakage.

Most of the annual heat loss from reasonably tight windows is from conductivity losses through the frame, spacer and glass. This is where double hung windows really fall down, (so to speak). All sliding windows have inherently cold frames compared to hinged windows, like casements. The sash in a casement window is "insulated" on the inside by the hardware cavity. The sash in a double hung window has no such advantage.

Another inherent thermal weakness in any sliding window is the meeting rail. Thermally it is the weakest part of any sliding window. The upper sash in a double hung not only loses heat through its outer face, but also through its lower edge. It is cooled on two sides. That's why the bottom edge of the upper sash experiences condensation before the lower sash.

Talking about the thermal performance of the window frame is a bit absurd in the average house. Sure if you are building with r-40 walls in Northern Minn, then go for it.

But suggesting that anyone will know the difference (or pay for the difference) between window styles is a little hyperbole.

All new windows are tight from an infiltration standpoint with the exception of horizontal sliders. I absolutely guarantee that more air comes through my double entry doors than my 40 double hung windows combined.

Focusing on window styles from an energy standpoint is a distraction.