A good rule of thumb is to replace your harness whenever you replace your rope; if you climb every weekend, replace it every few years. Also, replace it after any significant fall, even if everything "looks" okay...
do people really buy harnesses every time they replace their rope? that seems very excessive. I'm replacing my rope after about 1 year of use (had to chop an end and i want at least 60m), but my harness looks fine.
"Unthinkably good things can happen, even late in the game." ~ Under the Tuscan Sun
So I guess the belayer should replace their harness too after a significant fall. And what about the webbing portion of the draw... Shit Bcombs I won't be able to climb with you anymore. I just won't be able to afford it.
The only time I have had to replace a harness was when my weaksauce Petzl Corax harness rusted to shit! Every piece of metal on the thing was rustier than the cars you see in the backwoods of the red!
I don't agree with that rule because I wear my ropes out quickly. You just got to know when your harness is not safe. The seriously frayed tie points on mine was the red flag (after two years of use).
man my harness is getting pretty ghetto. I think it is about 8 years old. but then again, since i onsight everything, I haven't fallen on it yet so i guess i don't need to replace it.