National has pledged to insulate every state house by the end of 2013.
Prime Minister John Key today announced the party's housing policy, which includes continued investment in better state housing and insulating every state home built before 1978, when insulation became standard.
"This will ensure thousands of New Zealand families have a brighter future through living in warmer, drier, and healthier homes," Mr Key said.
Funding to insulate the remaining 4600 state homes built before 1978 would be allocated from within Housing New Zealand's existing budget.
More than 133,000 privately-owned homes have also been retrofitted with insulation under the National government's $347 million insulation and clean heating scheme, which subsides up to $1300 of the cost of insulating homes built before 2000.