to be more steady, and no hassle, just calculate it 4 days, u and ur partner, the middle room, and the single tenant...
basically if 300, u will be paying 50 extra if u dont mind..if ppl canot tolerate then u cant do anything, but u can cincai n let it go if just normal argument..or u can monitor ur usage oso, off the aircon for a day n compare.

n regarding the streamyx, tell them no torrent during day n night time...midnite then ok..or allocate each room with 1 IP add...