I suggest creating a special door that would minimize entry of dust, pollen, and bugs while keeping precious air-conditioning in.
It seems to me I have heard somewhere about it.
So new design contains special strips with infrared sensors that would open to the approximate person entering the office. Great! New automatic door would ensure cleanliness, comfort, compactness as well as cool-factor. There is nothing impossible for modern humanity that fills me with anticipation of this door soon presentation!