These are more properly called "Casement Windows" - as most people refer to the windows that open like this but extend all the way to the floor as French Windows or French Doors...
...and there is hardware available that allow them to be propped open - they're called "Stay Arms"

I lived in Paris for a summer in an apartment building built in the 1700s, and my apartment had them. I always had them open when I was home, and never had a problem with bugs (and I am very spider-phobic). I can't remember how I kept them open, but don't remember a big problem with the flapping around.

I did, however, start to close them at night after a friend mentioned that while staying in a hostel in another part of the city some thieves had somehow climbed from the rooftop in through a window and stolen some stuff. I didn't see how that would be physically possible with my 6th (really 6 1/2th) floor apartment, but it freaked me out enough that I slept with them closed after that. Luckily it was a cool summer.

Ah, Paris. I loved that little apartment...

I absolutely loved my giant windows while living in Germany, and I lived out next to a field. It was lovely. The view was beautiful, rustic. I never had problems with bugs, spiders yes, bugs no. **shiver** I can't say anything bad about them. They were heavy and nice. :)

I have these in the US, or at least, I have the divided up panes that swing in, and I adore them. They are a good portion of the reason I bought my house. I have little square ones and long 3-windowed sets.

So far I have had no problem with them staying open, my hinges seem to allow it pretty easily (I'm sure some 4d-40 would solve that but I like how they are now). The hardest part for me is finding window treatments. I actually had it as a "good question" on here before... the little teeny square ones I may eventually make roman blinds for, and the large 3-panel one, will probably remain 'naked'.

i love these windows though. completely charming. lucky you! :)

I dream of someday living somewhere where I can live with open windows and no screens...
I hate Florida :(

I lived in Florence, Italy or a summer and absolutely adored the casement windows. Ours were open whenever we were at home, and sometimes when we werent since we lived in the 4th floor of a 6 story building. I miss a lot of things about living abroad, but opening up my windows to lean out and watch the people on the piazza is definitely one of the biggest.

I have to second (or third or fourth) the nostalgia of living abroad. For me it was Istanbul...

I have similar casement windows in Sydney in our 1920's house. Our windows swing out so treatments are not a problem. Having no fly screens is a problem because flies and mozzies (mosquitos) are in a abundance in summer time. There are fly screen solutions which are on our To Do List.

I live in Los Angeles and these windows are common in houses from the '20s and '30s, especially, it seems, Spanish Colonials, but my humble cottage is a sort of English - Spanish cottage hybrid, and keeping with the hodgepodge theme, I have casement windows in the living room and double hung in all other rooms. Here, there is just a big screen attached outside the window to deal with bugs. I love my windows and they do have provide a fab look. . . sometimes challenging in the window treatment department. Right now, I'm using drapes, much like the treatment above.

The windows I had in Germany were fantastic. Similar to these, but better. If you turned the handle latch down, they swung open like these, and if you turned the latch up, they would open just a few inches in at the top (if that makes sense). I really miss that style of window and I wish they would spread to the US! The lack of screen, though, I guess would be a problem in a lot of places.

I had very handsome unscreened windows when I lived in England, and I loved the unobstructed view, so romantic. I did not, however, love the five or six months of bug bites. When another girl in the building complained about ladybugs in her room, I thought she was being a bit whiney. I mean, what's so terrible about a few adorable ladybugs? Then she showed me...and I had to agree. Five or six hundred ladybugs is really too many for one bedroom.

I lived in Amsterdam, and we had the full doors that swung inward.

There were no problems with them moving against our wishes. I got used to the occasional fly hanging out. The only consideration we had was to make sure the curtain rods extended enough on each side as to be able to push the curtains out of the way when opening the doors. Easily, I'd trade any day for those kinds of windows/doors.

They were brilliant. Summer was the loveliest thing, having those doors open, with the breeze making the curtains flutter.

Vacationing in Italy (& France?), one of the window-related things I really appreciate was wood shutters (the closeable kind -- not decorative, like in the U.S.), to keep the place cool if needed, or keep the room super dark at night, for a great night's sleep.

@jamie I went to Germany a few years ago and loved those windows!!! I'm still trying to find them in the U.S.

I had them in one apartment in Manhattan, and they were leaded casement windows. Wonderful. Any number of door and window manufacturers make the wooden versions, but they don't seem very popular in this country at all. Too bad. They're lovely.

We have them in our 1906 home in Ogden, UT. Its north of salt lake. They are original to the house. I love them, but I did build screens to keep our cats in and pests out. I just built simple square frames that fit into the window casing, and stapled on screen. voila! I also struggle getting them to stay open, but putting my curtains to the inside helps pin them back as long as its not super windy. The screens also have stopped my curtains from being sucked out the window on super windy days!!
We debate about replacing the windows often.. its hard to say whether its better to keep them original and true to the home, or replace them with new vinyl windows that are eco friendly versus the single pane french windows.

@Minchee, Jaimie, Meirad & All Others Who Love German Windows -

I agree wholeheartedly. I cannot tell you the number of times here that I wish for a good "gekippt" German window with shutters to let in the breeze while I sleep. American windows are simply not the same.

I just moved from Paris and I too had these amazing windows. I lived on the 6th floor so I felt very safe (thieves would have to climb lots and lots of stairs and then figure out how to get to the roof in order to break in via this method). Mine too flopped in the wind but my landlady used a marble salt and pepper shaker tucked into each window corner which kept them permanently ajar. i've also seen people use a tiny piece of wood that rested on the windowsill, try hitting up the BHV for twee wood. good luck!

ah yes! the excellent windows in Germany, we had "rouladen" on them as well to shut out all light and much of the noise when we went to bed. :)

I have these windows in my 1926 spanish bungalow in Los Angeles. We have screens, which is nice. But...

My windows are unfortunately in very bad shape and need to be replaced; however, I won't be replacing them with windows that swing in. Here's why - my house is 800 sqft and when open, my french windows eat into the space big time. So, I will replace them with beautiful windows that swing out.

We have french swing windows inout house and we love them! We do have storm windows on the outside that provides us with a screen. When we were trying to decide what to do with ours (100 years old) we found some frech swing windows at Pella. We were lucky and found someone who is restoring our windows .

We have the German windows that open on the side and on the top. We just had them installed this fall and today I opened them up as it finally was warm in New York. They are available through SorpetelarUSA and they are fabulous.

I have big casement windows that open outwards. But I have screens. Otherwise, my house would be filled with flies, roaches, moths and mosquitos. The "benefits" of living in a tropical area. There is no quaint street to look out on though, just two big mutts running in the yard.

When I lived in Italy, there were roller shutters to the outside of the building controlled via a handle on the inside. You could open your windows inwards and then roll down the shutters.
Here in Hong Kong I leave my wondows and French Doors onto the terrace open all day long with no screens or curtains/blinds - just a plug in mozzie repellant. It's fine.

In Paris many of the casement windows have exterior folding metal "covers" that one can close and lock at night. These covers usually have vented slits cut into the metal for ventilation. The air flows in but the light/bugs/burglars are kept out. Ingenious design and usually quite attractive.

Like others posting here, we had these windows in our upper level duplex in Echo Park, LA. One con not mentioned is that we could never open ours because we have indoor only cats. They would have immediately escaped and be gone forever. We ended up building a portable screen that we'd hook in and out when we wanted a window open--that way we could have a breeze and the kitties would stay imprisoned inside.

I lived with this kind of window all through my childhood. It's possible to put screens on the outer window frames; that's no problem at all. And the screens can also be on hinges.

If the windows are swinging open then perhaps there's something wrong with the hinges? Maybe they need tightening or you need a heavier hinge?

I love this kind of window. You can open the window and really get air into the indoors. You can lean out the window, no problem, and without contorting your body. I miss them a lot.

The older french windows with a larger oval knob were easier to keep a crack open and let the breeze through. We call that to leave them a l'espagnolette. Unfortunately, the newer ones don't have that option. Maybe because of the new "climatization" or air conditioning? I live in Provence, and it is hot in summer, but not hot enough in the spacious rooms to have A.C. and I just keep the antique window at l'espagnolette for air. For mosquitoes, an outside curtain/screen can be installed, or a wraparound indoor voile curtain. To keep windows wide open and not banging in the wind, small hooks and eyes attached to inside of window and inside wall will do the trick. Paint to blend in.

To lend a little more clarity, many US window manufacturers make this type of window, called a "French Casement".

My house was built i the sixties and I have these windows throughout. They open outwards and some of them have screens on the inside. I love them. Aesthetically they look beautiful because of the double door framing and from the outside of the house it looks like a little cottage when they are all flung open.
I will need to replace some of them eventually because of wear and tear and am dreading it because they just don't sell/make these anymore.

I miss the Danish casement windows of my Copenhagen apartment. They open to the outside, so if you fancy putting your bed next to the window, you can.
I'm French. I have casement windows and I like them, mostly. But my bed has a big headboard, so it has to be away from the window. Bummer.

http://2.bp.blogspot.com/-TcT3mYySbYE/TaupE8RI7TI/AAAAAAAAABM/dw1nSE_r9hw/s1600/+Copenhagen+windows+Denmark+Felipe+Pilotto+Photography.JPG

As bepsf said:
http://houseofantiquehardware.com/s.nl/it.A/id.3572/.f

Keeping them ajar is easy: You block the left window between the knob and frame of the right window when you push them two. A not quite full twist to close should hold everything in place. If not, the BHV has child safety latches. These have the added avantage of security, less rattling if there's a wind, and setting the distance you want open. I have them on all my windows.
I find casement windows here in France to be swines on occaison as they don't always allow enough space between the top and the ceiling for curtain railings or blinds.
Sash windows (like at home in Blighty) are my favourites but they're illegal here in France. They remind the French too much of the guillotine - so much so they're even named after it!

My parent's french house had mosquito screen stapled to a wooden frame which you could place inside the window. This was great as it both secured the window open (no flapping as it fitted in the groove left by the open window) and stopped the mossies. You could probably make your own.

I'm French, and now, I'm wondering about American windows. Can't you open them inwards or outwards ? How do you clean them ?

The problem with Parisian windows is that they are old, so they can't stay put if you want to sleep with your windows opened. While I lived in Paris, I used to close one panel in the summer (using the "espagnolette" Virtuelsie talked about that I loved so much) and let the other panel float. In case of wind, it didn't work so well.

I moved to a house last year, and we changed every single window to open them French style, but also to just swing the top inwards for the night (no idea how to say that in English). It just seemed so natural to be able to open the windows fully, we didn't even think about other options.

We never thought about security while in Paris. Old apartments are totally impossible to secure anyway (at least if you rent), so, if we got robbed, we got robbed. Which didn't happened. I can't try to be opened and have a house closed to the outside, even if it's the dirty city.

I kept the habit here and I often leave the house to run errands while the back door is still open for the cat to go out. I guess I mind more worrying about house security and electronic alarms that about losing my electronics. Burglars will go after my state-of-the-art computer, phone, sound system, but I don't think they'll touch my son's teddy bear or my belongings with sentimental value, and that's what matters.

I'm spanish and currently living in Spain. The windows @jamie mentions are the common ones here, very easy because of their double functionality, and friendly to clean.

If you need a screen in order to protect yourself from bugs, birds, etc. you can install it in the outside part of the windows, there is no problem, I have some at home and they work fine.

I live in the South of France (but moving soon, boo hoo) and while I don't worry about mosquitos and thieves, I do have to contend with lizards who crawl up my walls and into my house...to the delight of my cat. I don't have drapes as I love the openness and light, but when a storm or just general wind kicks up, it can be a burden to open the window and force the wooden shutters closed. For some reason, the wind is always blowing against my favor... Still, I'll miss them...

Depending on where you are in Paris (Canal St. Martin for example) you might have mosquitos - especially since it's been a warm spring already. If you can't get some sort of screen (since you rent, it may be difficult to find a solution) another solution is to run a fan (you'll want to once Summer gets here anyways - few apartments have AC and it can get sticky hot in June, July & August).

From India:
I prefer the windows that swing out. They are better at keeping very strong winds and drafts out and less likely to get in your way. You can fit a screen frame on hinges to swing inwards.

Plastic screening material (in a choice of colours) that attaches to the window with stapled on velcro strips are also becoming very popular. They keep bugs out and allow you to open and close the window easily.

In India we also have iron bars or grills fitted on the window frame to keep burglars out. Some are very artistic and add to the beauty of the window.

In India, the older houses have a small block of wood on hinges mounted on the window/door frame. This block can be swung back when the window/door is shut and swung in between the window and the window frame to prevent the window from closing. This method only works to keep the window wide open.

Newer homes have a fitting like this

http://www.alibaba.com/product-tp/107064838/Casement_Stay.html

or

http://www.alibaba.com/product-gs/253540523/friction_hinge_friction_stay_window_hinge.html

For more info please google 'Window Stays'.

I love casement windows, but what was nicest about living with them in northern France was the lack of mosquitos. The thing I miss most is functional shutters, to keep the room dark and the house secure at night.

The house I live in now has casement windows from the '50s. They open out on a crank, but you can't open the whole thing because there is also a fixed pane. The screen is between the window and the inside, which makes them a nuisance to clean. Plus, they're metal single pane windows. I hope to replace them in the next couple of years.

My parents who live in Provence have windows like that in their modern house. Theirs are triple pane and much heavier than the older wooden models. They also have screens which work like american screens. Screens are pretty new in France -we never had those while growing up- and may not be available for all window sizes but it's probably worth searching for them at the local big box hardware store.

I have seen french windows in some buildings on the upper west side, between riverside and west end. I once lived in an apartment with casement windows and liked how they aided air flow.

Many apartment buildings in NYC have traded out the older steel casement windows for newer windows, many of which are fixed pane. It's incredibly sad if you ask me because the older casements really add something beautiful to the facade and are really romantic looking from the inside.

Unfortunately if the windows are not maintained, and they usually aren't, they can be very drafty and that's a big problem during the winters.

couldn't you take some pretty ribbon and use it to loop the latch fixtures together while open? it would serve as a tether to keep the windows from flapping all the way back to the wall in the middle of the night.

I live in Italy. We replaced these windows because they are totally impractical. You cannot keep them slightly open. On a windy day, you basically have to shut them or be blown away. Because there are so many mosquitoes in the summer time, we had to turn out the lights and sit in the dark to avoid attracting mosquitoes into the space. The idea is very nice, but the reality is not.

I love the look, but in the U.S., they may be illegal if you live on an upper floor and have children (for obvious reasons).

ours are so old (1906) that they literally just have hinges on the side, there is no way to adjust the swing.. so yes very impractical on windy days... but so beautiful

I live in Chicago in an apartment building that was built in 1918, and we have these french style windows (with screens) that swing in. The only downside is not being able to put in an air conditioning unit during the muggy humid Chicago summer!