England put close defeats against Australia and South Africa behind them to claim a much-celebrated 38-21 victory over the world champions at Twickenham on December 1.
"We need to make sure we build on our performance," Lancaster told Sky Sports News. "We had a great win there but equally we're still disappointed to have lost the Australia game and the South Africa game."
It was not just the victory, but the manner in which they held off a spirited fightback from the All Blacks that led some to believe England were starting to come of age.
New Zealand scored two tries in three second-half minutes to close a 15-0 gap to just a single point before the hosts responded with Brad Barritt, Chris Ashton and Manu Tuilagi crossing the whitewash.
But Lancaster is refusing to bask in the glory of defeating the All Blacks and believes it will count for nothing if they rest on their laurels ahead of their Six Nations opener against Scotland at Twickenham on February 2.
He said: "What a great way to finish and a great stepping stone to take into the Six Nations, but the games go on and what we need to do is learn our lessons from that and take the positives, of which there were many - the consistency, the intensity and the way we kept playing for 80 minutes.
"That's great confidence for us and the players to take into the Six Nations but with Scotland round the corner we can put that to bed and recognise there's going to be a huge challenge coming our way and we need to be ready for it."
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