Broad said trustees should know the terms of the trust and its purpose and act in accordance with it.
"If you are looking after someone else's property you would think you would do that as a matter of course."
But many people who put their family home in a trust still treated it as their own by borrowing money against it or taking a rental income and putting the money straight into their personal account.
Broad believed some trusts would get wound up because trustees decided they didn't like the new rules or trustees may choose to retire because they weren't happy with the responsibilities.
Broad said trusts became fashionable to have around 10 to 15 years ago.
One reason people set them up was to protect their assets by gifting the value of their property over time so they would not be means tested by WINZ for rest home subsidies.
But a clamp down by WINZ stopped people from using trusts to do this.
Broad said there were still good reasons to have them such as protecting assets for those who owned a business or for setting up ways to support children who did not have the capacity to take care of themselves.
Broad said it could be two years before the changes came into force as the bill still needed to go through the select committee process.