Regardless, he said, "I'm pleased with the progress that we've made. There's a great deal more that I want us to achieve, but I feel it's been a good first year."
There have been more important achievements.
Mr Shaw's selection as co-leader played a role in the Labour-Greens Memorandum of Understanding, signed off this week.
A previous attempt by the two left-wing parties to campaign together in 2014 fell apart because Dr Norman's demands were not palatable to Labour. Dr Norman also upset Labour by questioning the costings of its policies.
Mr Shaw, on the other hand, had been more pragmatic and reasonable, Labour Party sources said.
Metiria Turei, co-leader of the Green Party, alluded to this when announcing the MoU on Tuesday, repeatedly referring to the role that fresh leadership had played in securing the agreement.
If Labour and Greens sweep to power in 2017, Mr Shaw could become Economic Development Minister.
But he won't say what portfolio he wants yet: "I want to serve in the capacity where I can make the biggest difference."
Mr Shaw has developed a rapport with Mrs Turei, who convinced him to run for the co-leadership in the first place.
"The quality of that relationship is really important," he said, noting that she had taken a larger share of the spotlight in the last year to help him ease into his new role.
While Mrs Turei and Dr Norman put on a united front in public, there were tensions in the relationship which affected the party and its ties with Labour. Mr Shaw won't discuss his predecessor, but hinted at the past problems.
"It is really important that Metiria and I have got a really solid foundation so that when we are working with our caucus and our staff we've got a united leadership team."
A former businessman, Mr Shaw came into the co-leadership promising to continue the Greens' push for economic credibility, which remains the party's major sticking point with swing voters. An invite to speak at the Wellington Chamber of Commerce this week was seen by some within his party as a sign that he is being taken seriously as an economic spokesman.
Speaking to an audience of business leaders, he said moving from the business world to Parliament was "like landing on another planet".
He admits to being "pretty tightly wound-up" during his first six months as co-leader, and says he struggled to feel comfortable in Parliament.
After a recent round of media training, he is now planning to step up and play an equal role to Mrs Turei.
"If anything, l'm learning to relax a bit more with the media and show a bit more personality."
