I have commuted on bikes for the over 10 years
Don't assume the office will not have a place for bikes.
In today's green environment it is good for business.
Even if the office does not have a spot check close parking garages.
If you do have to leave it out doors and it is a summer job then consider riding the 1980 Schwinn World Sport 10-speed.
That is a cool old bike with street cred.
As others have stated you have theft and the elements.
In or out your bike is going to get wet - keep is lubed.
I have two commuters.
A $2400 that I use when I can lock in the bike room at my gym
A $400 (used single speed) for when I have to lock in the open / outdoors
As for a new bike - if it is for commuting a road bike is not the best choice in my opinion
Any bike that will take larger tires
For commuting go 28mm or 32mm tire width (they are more stable and durable than a 25mm)
It can be a mountain, hybrid, city, touring, or cyclocross.
It is built to deal with many conditions and still for speed.
You get racers that are selling their old bike every season or two and get some great deals. Especially at the end of the season.
You can pick up nice bikes that were $2000 new for $800.
Put $100 in touring tires on a cyclocross and you have great street bike that is also good road bike.
The down side of cyclocross is if they are designed for pure race they will not have lugs to mount racks
If you are going to use it as a commuter then look for lugs.
A touring bike has a similar geometry and will have lugs.
Thing is you don't find as good a deals on touring as you don't have racers flooding the used market.
The only thing I would avoid for commuting is a mounting bike with shocks.
If you are dead set on a road bike still take a look at used.
This is cyclocross set up as a commuter (touring tires)
This is a bike you would not think of as a commuter but this is what I use when it is a route that I am going to ride sidewalks.
If I am going to bar and want a stable ride home in the dark this is what I ride (it has lights now).
And it is my play mountain bike - clearly not the tires I would use for a dedicated commuter.
Got this for $800 - what I am saying is there are play bikes that also make good (short distance) commuters.