Marnus Labuschagne said it was "very special" to take a record belonging to Australia great Neil Harvey while making his first Test double century.

Labuschagne's 215 helped Australia reach 454 against New Zealand on the second day in Sydney, and it made him the highest-scoring Australia batsman in a five-match home Test campaign.

Harvey totted up 834 runs against South Africa in 1952-53, with Labuschagne going to 837 after his efforts in the matches against Pakistan and New Zealand.

The feat earned Labuschagne praise from Harvey himself, with the 91-year-old telling the Sydney Morning Herald: "What he's done has been very good. He's got discipline and concentration. It looks as though he's going to be around for quite some time. He might pinch some of [Steve] Smith's mantle."

And 25-year-old Labuschagne, who made his Test debut just 15 months ago, was full of pride at his achievement.

"Obviously that's very special, going past a player of that calibre," Labuschagne said.

"It's hard because, when you're midway through a game or series, you don't really have time to stop and reflect on the summer that you've had.

"Looking at it, it's been a very special summer but I think the real privilege is playing in this team, with the camaraderie."

He began the day on 130 not out and was eventually caught and bowled by spinner Todd Astle.

Labuschagne survived the nervous 190s, tottering on 199 for a while before a hefty edge off Colin de Grandhomme for four brought up the double hundred.

He said: "You do get nervous. You probably don't get as nervous as you would if you were on 99. I don't know why, but that's just the feeling. Probably when you're in the 190s, it's about not doing something silly."

New Zealand plugged away to reach 63-0 by stumps and are crying out for a contribution similar to that of Labuschagne.

Australia's double centurion could yet set another record in this match.

England batsman Wally Hammond holds the record for the most runs in a five-Test Australian home summer, with 905 in 1928-29 - a target for Labuschagne should he get the chance to bat again at the SCG.