"There's definitely been a lift in the [median] sale price ... one of the reasons is we've sold a lot more properties in the $500,000-plus bracket.
"I think we're starting to get more of a spinoff from the Auckland market."
However, Northland was feeling the impact of the Reserve Bank's home loan restrictions, introduced in October.
"We're still doing as many open homes as before, but it's quite noticeable the number of first-home buyers coming through has reduced."
The national median house price hit an all-time high in December of $427,000 - a $2000 increase on the previous month.
Record highs were also recorded in the Waikato, Bay of Plenty, Manawatu/Wanganui, Taranaki, Nelson/Marlborough and Canterbury/Westland.
However, the number of houses sold fell last month. Sales were down 18.3 per cent from November, and 1.1 per cent compared with December last year.
The number of sales below $400,000 dipped 14.4 per cent, which could reflect the Reserve Bank's home loan restrictions, which took effect from October, REINZ said.
"Five regions posted new record high median prices, with some regions, such as Manawatu/Wanganui, Taranaki and Northland seeing sharp increases that are unexpected given the general trend in prices in these regions," said REINZ chief executive Helen O'Sullivan.
She added that prices in some regions might have risen because of fewer sales in the lower price bracket.
"The effect is not seen across the board, however, with Auckland reporting a $20,000 fall in the median price from November 2013."
Meanwhile, banks are trying to lure customers with special deals ahead of an expected rise in interest rates.
Kiwibank has launched the latest shot in this season's "mortgage wars", promising $2014 to customers who transfer their home loan and everyday banking to it.
This comes before expected interest rate rises - predicted for March this year. APNZ
