New data suggests Hawke's Bay home buyers may be letting superstition influence their decisions.
Homes.co.nz, which publishes sales histories and values, has analysed the relationship between letterbox numbers and house values.
Its estimated median value for a property at number 13 was $333,000, the lowest estimate for any number under 20. The next lowest valued number was 17.
The most valuable street number in Hawke's Bay was two, with a median estimated value of $382,000. The next most valuable numbers were three and six.
Numbers six, eight and nine are considered lucky in Chinese culture. Those numbers were valued slightly more highly than the number four, which is considered unlucky in the culture.
Property Brokers regional manager Paul Whitaker said number two might have been more valuable because of its location.
"Probably it's on a corner so it's got more land around the house."
He said it would be more common in Auckland for Chinese buyers to shy away from particular letterbox numbers.
"I haven't seen it in my 18,19 years."
Homes.co.nz spokesman Jeremy O'Hanlon said the idea that a number on a letterbox could impact values was a little absurd, however number 13 seemed to drive down values in certain regions.
"It's funny that Whangarei seems to buck the trend and value 13 higher than all but the number 12. While the Bay of Plenty and Hawkes Bay seem to have a real distaste for it".
"Perhaps it's worth hunting for the number 13 in your property search to grab a bargain."