Harmer - who is joined by front man Ben Gibbard, guitarist Chris Walla and drummer Jason McGerr - has helped take Death Cab from cult indie darlings to a chart-bothering, Twilight-soundtracking concern.
That's thanks to their emotionally-charged anthems about failed romance, perfected on 2008's Narrow Stairs and songs like You Can Do Better Than Me and I Will Possess Your Heart.
That album wore its bleeding heart on its sleeve, but they lightened up and didn't lose any of their impact on last year's Grammy-nominated Codes and Keys, which proved to be their most successful album yet.
But Harmer says the band's four members never want to be so big they're performing in stadiums to tens of thousands of people.
"We've got to the point that we can play in some nice theatres, and people seem excited about seeing us play. None of us want to be a stadium rock band like U2.
"I don't know what else is out there that we're really desiring."
Despite the emotions behind their songs, Harmer says they've never been a band to attract the attention of stalkers.
"We've never really seen someone who's followed us to every show. We don't have any encounters that are stalkerish or illegal, so we don't get crazy violent obsessive fans.
"The music obviously connects with people but it brings out their sentiment more than their aggression."
And he called it "shameful" that they haven't performed in New Zealand before.
"It's really exciting that this many years into a career we can find ourselves in new countries and new cities. We're really looking forward to it.
"However the tours and schedules have been booked, we've never had the time or maybe the interest for us to get over there.
