I agree with Loops, being on the bottom floor will not mean having a bit of a garden and being at ground level so this is not necesarilly going to be a safer option. Ironically, in our
condo all the ground floor apartments have grills as a matter of course, and the higher ones don't. I don't know, mayb they think someon will jump in their window or something (that would be very hard being that the security guards on the gates are very stringent).
Make really sure that the landlord knows you want grills - we were stupid and didn't stipulate it when we signed the lease, and now they won't pay for it. It just isn't worth the anguish...
Don't think "prison bars", they are usually nice colours and decorative.