This would be similar to the Toggleable lights from UDK. The shadows and indirect lighting would be baked, but the direct light would still be dynamic. This was great in UDK since you could have real nice baked area shadows from lightmass, but still have a dynamic light source that rendered out correct specular and normal information on meshes instead of baking that stuff down into the directional lightmaps.
The draw back of this was shadows cast from toggleable lights wouldn’t affect dynamic objects which created a bit of discrepancy. However in your arch viz case where the majority of the scene is static anyways that would be fine.