Northland landlords are lagging behind homeowners in taking up a Government offer of free or cheap home insulation.
Almost 1200 owner-occupied properties have been insulated in Whangarei and the Far North since the scheme began, compared with less than 600 rental properties.
The Green Party says the figures obtained by the Northern Advocate confirm fears the publicly subsidised scheme would fail those who needed it the most.
Healthy Homes Tai Tokerau spokeswoman Mel Peters agreed more insulated rental homes should be a goal for the Warm Up New Zealand: Healthy Homes initiative.
"We can't forget there are more and more people renting these days and we need to make sure they know, and encourage landlords to insulate."