Can I ask how much he gets out and about every day? My dogs get a lot less exercise than they did when they were younger (partly because I'm a bit restricted with a toddler at the mo (she starts nursery in Jan woooohoooo!) but also because they simply don't need it as much and have calmed down a lot as they've got older - so one good walk a day plus all the goings on of a family and interaction they get here all day here and a big garden to do 'stuff' in and play together , is ok for them at this point. But young dogs do need a lot more structure and regular short periods of activity outside as it's a very stimulating environment for them - I'm asking again because as you don't have direct access to a garden, I guess he's not able to go out and potter much and have a good investigate and sniff during the day also? It's possible that without that, he's finding other outlets for his energies and brain which are obviously undesirable to you and neighbours...
Just a thought....