It's not a message heard often in an era of runaway house price rises: property investment carries a risk.
It comes from the Financial Markets Authority (FMA) which is supporting the Commission for Financial Capability's Money Week in helping New Zealanders plan for their future.
The FMA stop short of any kind of comment on whether there is about to be a burst housing bubble - but make the point that property is typically only part of the mix in professionally-managed investment portfolios.
The latest KiwiSaver Report from the FMA shows just 8.1 per cent of the average KiwiSaver growth (high risk) portfolio is held in property assets; the conservative (low risk) portfolio average is 2.3 per cent.
That's a big hint - even to those New Zealanders fortunate enough to own their own home and have a KiwiSaver nest egg growing and for whom buying a second property is a tempting investment after large recent rises in house prices in Auckland, in particular.
But FMA's director of external communications and investor capability, Paul Gregory, says: "Property investment is a concept most New Zealanders are familiar with, which is probably what makes it so popular. However, having the majority of your investment capital in property could mean you have too many eggs in one basket. Little or no diversification increases the risk you won't achieve your financial goals."
Those seeking to invest in property should have done their homework and be comfortable with the level of risk involved, the cost, and the expected return relative to other investments, he says - and should also bear in mind property prices do not always rise.
From 1974 to 1980, New Zealand house prices fell by around 40 per cent in real terms; in the year to March 2009, house prices fell by 9.1 per cent in the wake of the Global Financial Crisis. Elsewhere in the world, price falls were even steeper. House prices in Dublin fell by 57 per cent from their peak in 2006 to their low in 2010.
If your retirement plan is to buy a rental, you could be in trouble if a decline in property values hits just as you're about to retire. Property values could take many years to bounce back following a crash.
Given the costs of owning property directly - rates, insurance, maintenance included - there may be lower-cost investments that will provide a good return while diversifying a portfolio, reducing overall risk.
"If you already have property investments, ask whether these are meeting your investment goals - and if they are, whether you really want to put more of your capital in the same basket, or would be better off buying something else that will provide the return you want," says Gregory.
"For example, if a KiwiSaver fund already has property holdings, increasing property exposure might be achieved simply by increasing contributions. Investing in a managed fund such as KiwiSaver removes the risk of unexpected costs involved in the day-to-day management of a property."
Those not keen on locking in their investment until retirement can invest in other funds. Managed funds enable investment in different types of assets, even if investors don't know much about them.
Professional investment managers have contributors' funds invested in a wide range of assets, including shares, property, government bonds and other fixed-interest investments, both in New Zealand and around the world.
Gregory says before investing - in property or any other asset - you should have a plan in place, with clear goals and an understanding of your attitude to risk.
Investment choice is the third of three steps to wise investment planning recommended by the FMA - the first being to set investment goals. Second, understand the basics of investment - by researching and comparing choices, finding the right balance between risk and return, finding the right mix of investments, spreading investments to help smooth out the ups and downs and understanding how investments grow and compound over time.
"There are a lot of questions you should ask yourself, and a lot of decisions to make, before you can be confident of making sound investment decisions," he says.
Those not comfortable doing their own investment research, or who don't have time, can be helped by a financial adviser.
•The FMA is the New Zealand government agency responsible for financial regulation. They are part guard dog (they regulate financial markets) and part guide dog (they provide information to help New Zealanders make better investment decisions).