What is the equivalent of a 2:1 Hons degree from a British University in terms of the New Zealand GPA system?

I am wanting to do further study in the UK and need the equivalent of a 2:1 degree. I understand that in the UK hons is built into a degree, while in NZ one must complete an extra years of study to obtain hons. In NZ I have a GPA of about 6.0 (B+). Do I need to obtain hons in NZ to have a 2:1 degree or is my B+ average enough?