would work, but i think it's easier and uses less redstone torches if you do it more like this
Yours does work well and takes up a lot less space. It also locks both the inside plates and the outside plates, so that I can still approach the door to kill whatever is following me (My base is very close to a large overhang, mobs are always there :happy.gif:)
Nbord's design works well too, because the inside plates can either ignore the lock, or be lockable too. I'll probably use both designs at different places in my fortress. Thanks for the help everyone! :biggrin.gif:
This is the design that I use. It locks both the inside and outside pressure plates, also it includes a switch that you can use to keep the door open (even when the door is locked). Which is helpful if you lock yourself out somehow, since you can just pop the switch on the other side of the door.
Took me about a month to try and get it as compact as it is now.