Unfortunately, when it comes to shared gardens there can often be challenges. For example one person/family might use their space more dominantly e.g. out there a lot, people having bbq's etc. This can discourage the less dominant people/families from using their spaces. Not saying it's right however that's often the way it is.
When you say your kitchen's on the second floor, do you mean two floors up i.e. ground floor, first floor then second floor (kitchen)? If yes, surely they can't see that
much of what's going on if they're in a ground floor office? Unless your rooms have longer windows i.e. that go closer to floor level but even then.
You could always cover the bottom third of the glass with something like this?