2-family house, 2nd fl rented, stairs

[dnk]

My question concerns a 2-family house where a landlord lives on the first floor and rents the second floor, to which stairs lead. There is also a small porch btw stairs and the entrance to the 2nd floor apt. My main question is who should be responsible for cleaning (including from snow) stairs? Also, in case the landlord gets ticketed by the city b/c the tenant keeps all kind on stuff on his front porch, who should be responsible? Your thoughts, as well as links/references to applicable laws, are greatly appreciated.