How to Lock a Partly Open Double Hung Window. 

Anyone who is considering this as an option, please be sure your window is actually a "single hung" window and not a "double hung" as the title suggests. The video is improperly titled. In a double hung the upper sash also moves, independent of the lower sash. This means the upper sash could be slid down from the outside as easily as if the window was not locked at all, as the wood is only blocking movement of the lower sash. If your upper sash is fixed and immobile, the window is single hung and this will work as described.

Thank you for the video and I appreciated your cat walking by and giving approval!

The velcro is an absolutely brilliant idea. I had already found some suitable wooden Posts But could not figure out how I would to get them to stick in place If somebody was wiggling the window. Thank you so much! Great idea.

I tried this earlier for my kids room (before watching your video, same inspiration with the sliding door) my husband went outside to test it and my window fell off its tracks and opened right up 🙃 So be careful and make sure you test this really hard. We ended up drilling an L bracket onto the window frame 😬 will probably regret that eventually. Lol P.S don't do what we did if it's your only window in that room bc you still need to be able to escape in case of a fire. We have two windows in that room and just needed one to be open for air flow.

Thanks for posting this... I will apply your idea with a slight change... I will divide the velcro attached piece of wood in 2 parts, to allow 2 different openings... one for when I am home (still safe) and a smaller opening when I a gone... (just insert & velcro the 2nd piece of wood back above the window).

This worked great on my single hung windows. I created two size dowels -- one to keep it locked in the shut position and one to keep it locked in the ajar position. The extra dowel just hangs out from another piece of velcro next to the window behind the curtain

Easy fix for this situation. Thank you for sharing your excellent idea and instructions.

Bright solution, thanks Brighton! 😁 ☮️❤️😎

What a terrific, and simple to do, idea. Thank You!!😃

Great idea!

When a double hung window is unlocked like this, can't someone just slide the top panel down since it is no longer locked at the midpoint anymore? That's what I found with my windows when I tried something similar. I would love someone to tell me how to keep the top panel in place while allowing venting like you showed.

It’s good that you could easily remove the timber so to use the window as a fire escape. However, a burglar could easily get his arms through that opening and with a piece of timber or a piece of steel could easily unhook those Velcro timbers and get in .

Of course we ALL need to keep in mind... if someone wants in... they'll get in.

Love it!

I just want to prop a window all the way up. Maybe this can do the trick? The window has one spiral balance broken off that I need to fix. It's a vinyl window. This should be easy??? I mean the window panels can be tilt popped out. I still haven't got my parts to tackle this. I was, in the moment thinking oooo just use a dowel, lol. The window opens. You must hold onto and lift the top window while lifting the bottom window to open it. The right side balance has enough tension to hold the window open. Of course the top is also open by 12 inches. If I can prop it up, until I get it fixed, that will work by holding top half fuly closed while the bottom half is fully open. If you have ever fixed a window balance by all means put a tutorial video up.

UNFORTUNATELY... from the outside a thin strip of metal can fit between the sashes. When worked it can pry the piece of wood away to gain entry. HOPEFULLY you'll hear it when it falls to the soft carpet down below. I DONT RECOMMEND leaving this system in place while you're away. Ps I've learned about this little trick because my husband did it to break into my home. I'm still searching for a better solution. Probably bars. He's even gone as far as removing the window glaze and taken the glass out. I welcome any suggestions 😊

I went a stage further and built a nuclear reactor with radioactive particles that if a burglar touches kills him stone dead ,it is disguised to appear that its a bottle full of coins in plain view .

Your a genius, thank you so much

I use rubber mat under my saw guide so it doesn't slide on the table top

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