Much depends on how many worshippers there are. In the early 1980s, there were no Sikh Gurdwaras in the greater Boston area, at all.
However, there were several Indo-American Sikhs that would host worship services in their homes, and there was a group of largely western Sikhs (mostly converted) that held worship services around the city, wherever they could find room. By 1990, one group had bought an old church and remodeled it in to a temple, the other group had built a small Ashram in a more remote community. Since then, there have been one or two other temples that have opened up.
Even with the physical buildings having been built, it is not uncommon for a Sikh to host a keertan service in their home. We don't require that our religious services be lead by a priest, it can be done by that meets a certain set of qualifications (knows the prayers, has made a formal commitment akin to a baptism, etc). However, once a community reaches a certain size, it is much easier to have a building as a central gathering place, and hire a priest to lead the services.
Food is involved also Each time a service is held, one family arranges to cook a full vegetarian meal for all attendees, regardless of their faith. One of the reasons why the meals are vegetarian is so the meals do not violate the rules of other religions.
I recently trained Gatka with a Sikh martial arts group. Exhausting but great fun. Can dance a bit too now!
Whether in a house or a larger building though we all congregate don't we? It must be part of the human condition to want to worship with others perhaps?
What I'm looking for is actually more things we have in common rather than put us apart, I think we've had enough now of the differences that divide us, sometimes nastily, so perhaps a few similarities would be good. Food is good!