RESPONSE: We will try to answer to the best of our ability without seeing first-hand the rooms or area near the space. We offer an onsite assessment as part of our service package. That assessment would provide a definitive answer.
As it relates to your conference rooms and offices and the LOCK OUT option. As a general rule, while we say Lock the Door, that will not be the sole determining factor on whether to attempt a lock down in a given space. If a person has been trained to properly barricade the door it will not matter if there is a lock, however, a lock is a very fast first layer providing more time to continue the Lock, Layer, Reinforce theory. The most important concept is creating layers to slow and deter the suspect from attempting to make entry into the space. Many times (in our hands-on training courses) while doing the LOCK OUT scenario, we do not allow students to use the lock and only rely on proper barricading to keep the intruder out of the room. It can be done very quickly and securely when properly trained to do so.
From the description of the space you are concerned with, it is not the lack of a locking mechanism on the door that concerns me, it is the large glass wall. We have seen this in many businesses that we have worked with - and while they are very nice in appearance - it places anyone using the room at the moment of an attack in the precarious position of being in a "fish bowl."
So our suggestion would be, this is an area that leaves two options, GET OUT and TAKE OUT. So anytime someone is using this space, they already know that because of the design of the space it does not lend itself to LOCK OUT. They need to have a plan for getting out of this space and into a nearby room that can be locked and barricaded, or continue to get out of the area. They should ask themselves where they would attempt to go if the threat came from this direction or that direction (scenario role play).
As a last resort, if a person is unable to GET OUT due to the close proximity of the threat, be prepared to fight and mentally identify items in the room or surrounding area that could be used to fight with. This pre-planning mindset assists each individual in identifying their proper response for each space so they can cycle to the appropriate response faster in a crisis.
One final option (it can be pretty expensive) would be to select/designate rooms on each floor with glass walls as ‘safe rooms’ and equip them with transparent ballistic window film. Your company could designate 2-4 rooms on each floor as ‘safe rooms’ and then install this window film on each of these rooms. Then practice getting to these rooms - and using LOCK OUT techniques.