Some who purchased very close to the November 2021 peak, especially if they had a smaller deposit, might've even found themselves in "negative equity".
This means your mortgage is larger than the value of your house, and your equity has been wiped out.
Let's say you bought in November 2021, when the national median house price was $925,000, and you had a 10 per cent deposit of $92,500.
Your mortgage would've been $832,500 at the time, and it would still be quite close to that level today, as the bulk of your payments since then would've attacked the interest, rather than the principal.
Based on the 12.7 per cent decline we've seen since then, your house would today be worth just under $808,000 - slightly less than you owe the bank.
That puts you in negative equity.
There will obviously be exceptions to this. Some people might've bought near the peak but snared a bargain, while some regions have held up better than others.
Wellington and Auckland have seen declines of more than 20 per cent, while Southland, Nelson, and Taranaki have only experienced falls of 3-4 per cent.
The Reserve Bank estimates about two per cent of current mortgage lending represents people in negative equity, but it expects this to rise if house prices keep slipping.
A further 10 per cent fall from here would see the proportion of mortgages in negative equity rise to 7.3 per cent, while it would jump to 18.3 per cent if they fell another 20 per cent.
That might sound outlandish, but remember, national house prices rose a staggering 46.9 per cent between December 2019 and November 2021.
Much of that was due to interest rates collapsing to levels we've never seen in our history - a trend which is now reversing at pace.
A 10 per cent fall from here would simply put prices back at November 2020 levels, down 21.4 per cent from the November 2021 peak, but still 15.4 per cent above December 2019.
That sort of decline, or something larger, is far from impossible.
Finding yourself in, or close to, negative equity isn't the end of the world. The "losses" are only on paper, and most of us buy homes to live in, rather than as money-making schemes.
The housing market will recover over time, so if homeowners can hunker down and keep making mortgage payments, their equity will be rebuilt, sooner or later.
However, this all becomes a much bigger problem if the economy deteriorates, unemployment rises too much, and more households find themselves in financial difficulty.
Mortgage rates for terms between one and three years are currently about six per cent, while the average rate people are paying is a much lower 3.8 per cent.
There are many households out there yet to re-fix mortgages at current rates, and when they do, they could face sharply higher borrowing costs.
Combined with dented confidence on the back of declining housing wealth, this is a recipe for reduced activity and lower spending.
Mark Lister is investment director at Craigs Investment Partners. The information in this article is provided for information only, is intended to be general in nature, and does not take into account your financial situation, objectives, goals, or risk tolerance. Before making any investment decision, Craigs Investment Partners recommends you contact an investment adviser.