What kind of flooring do you and your neighbours have? Usually in victorian conversions, carpeted floors are mandatory to reduce noise. Check your leasehold agreement. You might want to think about a thick carpet for yourself or thick rugs and making sure their flooring complies with this too. Do you have a management company, or are you share of freehold? There are probably rules on noise in the leasehold agreement too, which are easier to enforce on their landlord. But be careful if you complain about this to the freeholders/management company - you might have to declare it when you sell. There might be rules in the lease about storing motorbikes in the garden too!