Minister of Energy Megan Woods said the Government now meets 90 per cent of the cost, so she expected top-ups from community organisations would make retrofits free to many applicants.
She encourages homeowners to find out if they are eligible and apply for a grant.
Retrofitted heaters are capped at $3000 including GST.
For instance, homeowners looking at having a $3000 heat pump installed will only pay $300.
"It's important that you make sure family members and friends know about the grant offer, which makes insulation and highly efficient heating much more affordable," Woods said.
"Insulation and efficient heaters don't prevent the spread of Covid-19 but a warm, dry home does protect the most vulnerable and decreases the risk of hospital admissions from respiratory disease."
To be eligible for the grant, the home must have been built before 2008 and be in an area identified as lower-income.
For more information on whether you're eligible for a grant, visit warmerkiwihomes.govt.nz.