The 1100 has a built-in antenna only. My comment was really for general interest. However, you may be able to use the 1100WGB, depending on the distance between your buildings. If you use a 13.5dBi yagi antenna at the AP and assume a 2dBi antenna in the 1100, mounted behind a window or in a NEMA enlosure. Using the max EIRP within Europe, the Cisco Bridge Range Calculator shows 0.4miles @11Mbps and 1mile @1Mbps. Outside Europe, it shows 1.8miles @11Mbps and 4.5miles @1Mbps. However, it has already been stated that you can not use this combination above 1 mile, due to timing constraints, but the figures above do indicate how much signal strength you would have in hand at the shorter distances. I would not recommend using the 1100 at maximum range, as the omni antenna is more likely to pick up interference from other directions.
So, if your buildings are just across the road to each other, no problem.
