Well, what is the style of your house? That was our biggest consideration of casement vs. double hung. On our traditional brick house, DH looked the most appropriate. I personally wouldn't mix styles on the front elevation. And again, as far as the mullions, it depends on the style of your house, although I feel that with the exception of some very modern homes, most houses look better with an appropriate mullion pattern of some sort.

My DH and I were just talking about this. We are building a farmhouse and I love French Casement windows. In the end, we decided to go with hung windows to save money but I had this picture on my Pinterest board showing a mix of both. They are French casement but still, you get the idea.

Here is a link that might be useful: Mix of Casement and Hung

It depends a lot on the style of house, but if they are on separate masses of the house it might work fine.

If you aren't going to be opening the windows in the garage, why make them operational at all?

grids always add cost to the windows. Casement is typically more expensive, however casement windows are more efficient then hung windows. They seal up better and for a longer length of time. Depending on the window company, you can get casements to look like hung if you want. I always recommend casements to clients due to the tighter air seals they offer.

They are also more thermally efficient, have better views, and they ventilate much better.

A house that is for sale in my neighborhood (that I love) has both: double hung on first and second floors and casement on the third.

Here is a link that might be useful: Mixed Window Styles

Thanks for sharing the photos, very helpful!!

Are these casement or double hung windows?

They certainly look like double hung.

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....

@david, do you have a picture of your elevation you can share? Would love to see more pictures before we decide. :)

Most of David's cons with regards to casement windows can be overcome by using tilt and turn windows.

I don't have a pic available but what I have is the upper windows are casement with a grid in the whole window as opposed to a grid in the upper half of the other windows (DH). The casements are singles in a gable and a dormer (I never get these terms straight) and all the DH's are in window groups of 2 or 3. One of the "casements" is really a fixed window into unconditioned space above the garage. But it looks like a casement.

I forgot to reinforce the pro of air infiltration.

I think the key in doing this is being sure the lights are the same dimensions. We have a triple casement over our bathtub on the front of the house, the rest double hungs on the front with the exception of a small (2x3) casement on a garage bump out. We also have a casement in a bath (also a small one higher up for privacy) and a casement over our kitchen window.

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 built our new house with all casements and love them.

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.

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.

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.

I'd like to question the air infiltration argument that is always talked about.

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?)

From Green Building Advisor.com

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

From Thermotech's website:

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.

Thermotech of course is a company trying to sell their product.

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.