It has become commonplace for agents to request names and contact details - sometimes even proof of identity, prior to allowing buyers and/or Renters to inspect a property.
It is important to note that although it is not a legal requirement for people to provide their details with an agent at an open house, it can be a condition of entry to the property.
This can be confusing to some who claim that they have a right to enter, with anonymity, as it is a publicly advertised open for inspection.
The fact is that the property is open for inspection, but the owner can make any conditions of entry that they see fit. The agent is at the property as the owners' representative, and can allow or refuse entry as the Seller or Rental Provider has instructed. Would you let someone into your home if you didn't know who they were?
While under the Privacy Act, an agent cannot ask for personal details, the Act also details how the information is collected, stored and used by the collecting agency - in this case the agent. This information cannot be used other than for the purpose for which it was collected. The agent is required to have a Privacy Act collection notice displayed, providing all the relevant information. If you don't want to hear from the agent again, just tell them and they will not contact you, however be aware that they will not contact you about the imminent sale or lease of the property, or about other similar properties that may be of interest to you either.
If you refuse to give the agent the requested details, it is within their rights to deny you entry to the home; after all it is actually private property. If you refuse to leave, when requested to do so by the owner, or their agent, you commit the offence of trespass.
As the representative of the owner, the real estate agent has the right to request your details as a condition of entry to a property and may refuse you entry if you fail to comply with those conditions.