"Some landlords may believe the insulation in their rental properties already complied with the new rules but it may be old and damaged," he said.
All rental properties must have ceiling and under floor insulation which meets a set standard, wherever reasonably practicable, under new Tenancy Act rules from July 1 next year.
Mr Caseley urged landlords to get in quick while the grants were available.
"It's first in, first served," Mr Caseley said.
Tauranga Property Investors Association president Simon Darmody said Tauranga had a relatively new housing stock.
That meant the city did not have the same volume of old houses needing insulation upgrades as some of the more established towns and cities, he said.
"I think the number of uninsulated properties in Tauranga is relatively low if our members are an indication of overall rental properties across the city."
Plus the reported EECA figures failed to take into account rental owners using other subsidy schemes, or finding cheaper options to insulate their properties, he said.
Energy and Resources Minister Judith Collins said it was disappointing more landlords had not yet taken up the opportunity to get a grant towards insulating their rental properties.
"But I am confident that Energy Efficiency and Conservation Authority is working hard to promote the Warm Up New Zealand: Healthy Homes programme," Ms Collins said.
To qualify for the Warm Up NZ insulation programme
- The home must be built before the year 2000
- The owner or main tenant has a Community Services Card
- There are children under 17 years or adults over the age of 65
living in the home or someone with high health needs.
- Landlords of eligible tenants may be asked to make a contribution.
Go to www.eeca.govt.nz to find out more