Interest rates might be sinking but council rates are rising and that could drive rents up.
The latest Crockers Property Investment Index found about a third of landlords and investors believe rents are currently below a fair price.
Mortgage money has become cheaper but rates continue to rise and many owners might seek to pass those escalating costs onto tenants, Crockers indicated.
"A number of factors come into play when considering rental increases. An increase in local rates is the most likely to lead to an increase in rents (72 per cent, up 8 points), but other costs like insurance and property maintenance also play a part," Crockers said.
"Compared to the previous survey in July 2014, significantly fewer respondents are saying an increase in interest rates would influence them to increase the rent on their investment property," Crockers said.