If your office doesn’t currently have a policy regarding bicycles in the office, it’s most likely because nobody has given the management a reason to create one. It’s in your best interests to keep it that way!
I’ve seen the fear of dirty carpets get bicycles nixed from offices on more than one occasion. I think there may be a misconception from non-riders that bicycles are dirty. For the most part though, bicycles are probably cleaner than the shoes that trample the carpets daily.
Having said that, there are times of the year when your bicycle will collect snow, ice, rain, or mud along your commute. Make sure you take the time to get any of the big chunks off your bike before bringing it in the office. Until your bike has a chance to dry, put something underneath it to collect the drips. Paper shopping bags work good, but lately I’ve been using the pages from my old desk top calendar. Most of the crud seems to accumulate around the cranks, bottom bracket, and front derailleur, so be sure to cover that area.
Once your bike has dried, hide those drip catchers! Also, try not to block any vital office equipment, or make other obstructions that may inconvenience others. Don’t get noticed…fly under the radar! Anything you can do to maintain a visibly clean storage area around your bike will help you keep your preferred, secure storage on the inside of the building.