I've had this problem ever since I made my map. The windows are easily jumped out of if you just let a zombie break it down, jump, and crouch at the same time. I consider making the whole window smaller, but wouldn't this affect the zombies ability to get in too? Any solution is greatly appreciated. 

Use Clip texture on brush.

How do I do that? XD

How do I do that? XD

You make a brush by dragging it and change the texture to clip... (or player clip if you want zombies to be able to pass it)

I'm using the barricade from sniperbolt's tutorial prefabs. How can I change the texture and enable player clip (sorry I'm so nooby XD)

I'm using the barricade from sniperbolt's tutorial prefabs. How can I change the texture and enable player clip (sorry I'm so nooby XD)

Stamp the prefab and select the clip and change it. i would think the prefab would already have a clip tho.

I've looked everywhere, trying to figure out how to stamp it, I can't find it. Could you please tell me how to do it in a very simple way, because I only know how to do VERY basic mapping, so I'm super confused    I have no idea what stamping or brushes are.

I've looked everywhere, trying to figure out how to stamp it, I can't find it. Could you please tell me how to do it in a very simple way, because I only know how to do VERY basic mapping, so I'm super confused    I have no idea what stamping or brushes are.

There is a stamp icon in Radiant that you have to press. it looks like a stamp. to select the prefab, press Shift and click the window barrier. Then you can click the stamp. then all of the items are separated and you can movie them. This is as simple as I can get. you may want to look up a video about stamping if you still don't understand.

Turns out the stamp button WAS HIDDEN. The toolbar at the top was so big it went off screen. Looks like I found some extra tools XD. Thanks 

Welcome

Quick question. I FINALLY changed the red window box from "Mon" to Player clip. How do I merge the pieces back together? 

Quick question. I FINALLY changed the red window box from "Mon" to Player clip. How do I merge the pieces back together? 

Select all of the parts of the prefab and stamp it again.

are you serious? dont change the mon clip thats there for a reason, add a new "PLAYER CLIP" For the player only dont fuck around with the prefab AT ALL

Wait so I'm supposed to have a 2 red boxes overlapping eachother. One is "Mon" and one is "Player clip"? 

zombies will pass through clips on traverse anyway

so could just have 1 clip, and make it "clip", not mon or player