I have just done a quick google and found our highest Mountain is 12,316 ft AMSL, our transition layer starts at 13,000 ft, can't be a co-incidence?
Its odd how our layer is a mandatory 2000ft thick but the UK is dependant apon area QNH? that must be annoying having to work out which level you need to be as fronts come through etc...
Mind you our airspace is a lot less constricted in NZ wtih most of it Being G with a smatering of C.... and bugger all A class so i guess we are bit 'free and easy'