As has already been said, try and stick to 1, 6 or 11. These are non-overlapping. Another common setup is 1, 5, 9 and 13. These have minimal overlap, but are still mostly non-interfering with each other. Channels 12 and 13 are UK only - if you have any US kit (like a company MacBook I had a few years back, which was US manufactured), that will not see SSIDs on channels 12 or 13, and you will be limited to using 1-11 in that regard.
If 1, 6 or 11 doesn't work, opt for setting your AP to the strongest channel that everyone else around you is using, to avoid overlapping and interference. But their APs maybe on auto mode and changing frequently so this may be a futile exercise long term.
If this doesn't work, leave it on auto and hope for the best, or consider moving to 5 Ghz. I have just one SSID in that range where I am, nothing else reporting on my MacBook, so it seems to be an uncongested band right now. But give it a few more years, I'm sure that will change. I'm considering getting a 5Ghz ac-wireless access point right now, but purely to allow faster access to my NAS, not because I have any performance problems with my existing 2.4Ghz setup (even though the space around me is quite busy in that band, like yourself).
Edited by mixt (Thu 07-Jan-16 15:21:25)