marlia, not to fear-monger or downplay the enthusiasm here but just be careful about the possible extra loads to the building. Commercial occupancy will impose more loading to the structure than residential and could trigger failure unless anticipated in the design. That said, an office will add merely 10 psf of live load and may not be enough to cause alarm, so it's possibly your best bet safety-wise. On the other hand, floor vibrations from a pool bar, night-club, or a gym (!) will inconvenience you to say the least.