What is the number of people allowed to live in a1 bedroom apartment?

There is only a legal cause of action if at least one of these three cases applies:

1) If they are disturbing your quiet enjoyment of your property or creating a health risk, you may have grounds to terminate your own tenancy if the landlord does not do anything after written notice and a reasonable opportunity to take action. You alternately may have grounds for a lawsuit seeking monetary compensation for the loss of quiet enjoyment or habitability. This could motivate the landlord to take action, but note that it is a high "bar" to get over to show breach of the covenant of quiet enjoyment or warranty of habitability: there must be more than mere crowding or annoyance, but some condition directly and siginificantly impairing your use of your rented space.

2) If the number of people in the apartment, or number of unrelated people (since they are not married), exceeds housing code, you can report the matter to the housing enforcement authorities. This varies by municipality, so you should check with your local building department, police, and/or town clerk.

3) If the leases, including yours, contain restrictions on the number of people per bedroom or apartment, it may be possible to enforce that restriction (you would try to enforce it as a third-party beneficiary of the lease between landlord and these tenants).

There is only a legal cause of action if at least one of these three cases applies:

1) If they are disturbing your quiet enjoyment of your property or creating a health risk, you may have grounds to terminate your own tenancy if the landlord does not do anything after written notice and a reasonable opportunity to take action. You alternately may have grounds for a lawsuit seeking monetary compensation for the loss of quiet enjoyment or habitability. This could motivate the landlord to take action, but note that it is a high "bar" to get over to show breach of the covenant of quiet enjoyment or warranty of habitability: there must be more than mere crowding or annoyance, but some condition directly and siginificantly impairing your use of your rented space.

2) If the number of people in the apartment, or number of unrelated people (since they are not married), exceeds housing code, you can report the matter to the housing enforcement authorities. This varies by municipality, so you should check with your local building department, police, and/or town clerk.

3) If the leases, including yours, contain restrictions on the number of people per bedroom or apartment, it may be possible to enforce that restriction (you would try to enforce it as a third-party beneficiary of the lease between landlord and these tenants).