Before making any design decisions you should check with the local building department about the egress requirements. I would doubt that an awning window is legal for egress.

Thanks, I did look it up and an awning window is sufficient as long as it holds up on it's own.

Are these double hung sash windows? If so, look into sash stops, sash restrictors, retractable sash restrictors, etc.

Your idea might work too. If you want opinions on how it looks, include a picture of your house.

An emergency escape and rescue window has a minimum of 24" net clear height. You would probably only fit 2 windows in a 6' existing opening, besides 3 stacked window units would have pretty prominent "heads" (and muntins would exacerbate the look). I would double check that awning windows comply with code per the manufacturer you are interested in. They would probably need to open 90d, and not all manufacturers do that. You might have to look at tilt-n-turn to get matching awnings with casement/fixed, but the manufacturer still has to designate it as meeting code.

Blindly assuming the look of your house with a single 42"x72" window, you would probably be better off with a casement below meeting code and a small transom-like awning above.

At that size, and meeting your requirements, you might consider a tilt/turn window as an option.

The typical tilt/turn is the most secure window style that I am aware of, other than fixed, and fixed generally aren't very good for air flow.

The first time I ever saw one, along with several other folks, the first comment was that this looks like a window intended for a bank vault.

Even when in tilt position, the window is still very secure and is going to resist anyone trying to get past it while it still allows in more air than you would feel from an awning in your set up.

Any window that is open at grade is a security risk. The OP I believe is not concerned with risk when a window is closed, rendering the style of hinges moot.

Tilt-n-turn was only suggested to meet code when open, but do not meet the OP's desire to have only open windows that are out of easy reach from grade. Also, tilt-n-turns are quite expensive. It doesn't seem a good fit for this house. In fact, spending $10K on a few windows might be more than adding a mini-split for cooling on those certain nights (assuming you are a cold climate without existing forced air).

Also, if you split the windows vertically, note that the split will be at eye level. Your existing headers looks to be typical at 7' high (estimated from the 6'-8" of the door), so your sketch of the Living Room windows is misleading. It portrays a transom-like situation in a high ceiling, which you do not have.

IMO security with any window is a moot point . Where I live awning windows do not meet egress code not matter if they stay open or not Why not just do a simple window with the bottom allowing egress and air flow . Unless you live in high crime area hoestly if someone wants i the just break the window . Get a good alarm system with an added alram at the window.

Thanks 3onthetree, that's exactly it regarding security. Also, upon reflection, tilt and turn opens inwards, which would impede the functionality of the rooms inside. Sorry, I'm not sure what you're referring to about a transom-like situation. I simply outlined the windows that are already there, and drew in an awning with a grid along the top.

My new thought it to do one foot awning windows along the tops of all 4 windows. Then split each bedroom window in half vertically and have half of it open as a casement for egress. To meet code it would be a 23/21 split, which is my current hesitation.

Patricia, our area is opportunistic enough that people will climb through an open window on a hot night. That's what I'm trying to avoid.

For clarification, I was specifically considering the security aspects of the tilt/turn in the tilt position. When opened in tilt mode, there is no way that someone enters through it short of breaking the glass and crawling through, which is not something any normal person wants to do. Definitely not a opportunistic

In tilt position it becomes a really large hopper window opening in maybe 6" along the top or so, which isn't really intrusive at all, but it might affect window treatment locations, which is a consideration for some people. And while they are generally more expensive than other window styles, they are probably not more expensive than a double mulled awning/fixed/awning would be, and a heck of a lot more secure at any level.

The full open in turn position works great for letting in a lot of air, for cleaning windows from inside, and for egress, but it is rarely necessary when all someone simply wants to open a window for fresh air. The tilt position is usually more than adequate for that.

From the standpoints of functionality and security, tilt/turn's are considered by many to be the top-of-the-line product, but they aren't for everyone primarily because of their aesthetic and price. But for keeping people out, open or closed, there isn't a better window style available.

Here is a good video of tilt/turn function. For disclaimer, the windows are thermally broken aluminum, built in US, but I know nothing more of this company at all, good, bad, other. I am only posting the video as a good example of function because it's well done and quick.

https://www.vetrinawindows.com/styles/tilt-and-turn-windows