How to make Altbau windows childproof - Berlin

We live on the second floor, in a beautiful Altbau flat with tall double windows.
Each set windows have one simple handle that turn and the windows open like doors, to the inside.
It's a straight drop to the concrete.

Our 2 toddlers are just able to reach the handles.
Yesterday I found my son kneeling on the window ledge pulling himself up with the window handles and trying to open the window- am certain he'll figure it out promptly.

It's not possible to stay in the same room and to monitor the windows 100% of the time, we live real lives.
It's a straight drop to the concrete.

What do parents do here to prevent the kids from opening the windows?
Surely this is not a new problem.
We just don't have windows like these in Canada, and so I don't know what to do.

Suggestions and experiences greatly appreciated.

A window lock would solve the problem; either one fitted to the handle or to the frame. A local window dealer would be able to advise.

Most windows in Germany are the modern NT variety, and the most common form of childproofing for these is the tilt-first system, where a key is needed to turn the handle all the way and thus open the window fully.

Can you ask your landlord if he has heard of any options? Are there other people with toddlers in the same building who you could ask? You could also go to a Baumarkt or a baby supply store and ask there if they have some appropriate devices to keep the window from opening fully. Maybe google? You can't be the first person with this problem. Don't despair!

If you lock the windows, they can't be used anymore.

Is there enough of a sill that you could set an expanding child window guards for what sound like casement windows?

If both of the double windows come with a lever, you could simply tie them together but if there's a single handle for one set like you seem to be saying, it's a bit more tricky. You can look for some baby lock products like http://www.google.de/search?q=fenster+kinder+sicherheit

I am not sure what you mean by tall (how tall exactly) but if there is a window sill, you could get an F clamp in a hardware store and clamp a block of wood to the window sill which will prevent the window from being opened more than up against the block. It's crude and ugly but works.

I Put a hooked screw (Bent closed) in either window then clipped them together.You can always bog up the hole later. Our kids are bigger now but to be honest (and non pc) If I'd found one trying to open the window I would have given him/her a slap. They wouldn't have done it again.
People can say what they want to this, but my kids,and your kid's,life is what's important to me.
Dave

I suggest you remove both sets of window handles altogether to be replaced when the children are old enough not to use them accidently. This is what we did for my 3rd floor Altbau-living children. It's free and it works! The windows are out of action but the children stay inside. (Just ensure your windows stay locked when the handles are removed). If you have lower and higher windows, you may consider disenabling both sets of windows if the childern are good climbers!

We've got locks on a couple of our window for security reasons. My husband just exchanged the regular handles for locking ones that come with a key and can be locked or unlocked as you please.

I have to agree if you can't get your head round a simple lock and it is too expensive and complicated my wife had a simple solution. She simply took the child to the the front room, showed her the sixth floor window she had been trying to open and threw our little cocker spaniel puppy out. She then took our daughter downstairs to show her the results. Yes she was upset but seemed to understand. After this procedure she took the little one back upstairs and cut her right hand across the palm. There hasn't been a problem since then.

ps. We did get her a new puppy but a different color so she would know... the difference... so to speak.

HAL9000- I am utterly speechless and half inclined to think you are taking the mickey.
There's a movie you might enjoy it's called Das Weiss Band.

TO the rest of you, thanks for your suggestions.
A basic hook and eye from the hardware store has solved the problem, as with these particular windows locking handle can not be installed.

I am happy also that our window security solution had a cost of only 69cents per window. Much cheaper than the plastic alternatives on the baby care websites (not that we could find one that would work with our type of windows anyway)