In the event of an active threat, your first response should always be RUN if you can. But if you cannot run, your next option is to HIDE. Once you’ve locked the door, barricading entry greatly improves your security.
Which way does your door open? A trick is to look for hinges. If you see hinges, the door will open towards you (inward). If you don’t, it will open away from you (outward).
Barricading Inward Opening Doors
Because this door must be pushed into the room to gain access, placing heavy objects in front of the door will make it difficult to open from the outside.
Place a chair under the door handle
Stack furniture in front of door (or place furniture in a line from the door to the opposing wall, if time permits)
Barricading Outward Opening Doors
Outward opening doors are a bit more challenging to secure, but being aware of your available resources still makes security within reach.
Use a cord, belt, purse strap, cable etc. to tie the door knob to heavy furniture.
Tie the handle with a cord, belt, purse strap, cable etc., stand to the side, brace and hold on tight.
Tie a cord, belt, cable etc. tightly around the door arm.