Thank you all for the reply!
Jayjay: your "is overlapping" idea works better than "in collision", thank you! "Else" worked wonders for this case!
emoaeden: I only got the stable version of Construct 2 (prefer to work with stable builds), so I can't try your method. Thanks anyway.
zordork: thank you for the tutorial, it uses the basic principle from Jayjay - the only thing is that, as I specified, the doors should close if the buttons are not pressed. Instead of destroying then, I'm changing the animations (to open/closed). Maybe changing sprites altogether would be easier, not sure.
This is how I did it:
player is overlapping (sprite) - set button animation to "pressed"/ set door animation to "open"
else - set button animation to "default" / set door animation to "closed"
Only problem is if I use a animation (say, the door opening), it loops while the button is pressed - even if the animation is set to "not loop". Which is weird. So, for the time being, it is only working with non-animated sprites/animations with only 1 frame.