The Government's home insulation programme isn't good enough to keep houses in colder parts of the country warm, a new report says.

The Otago University report, obtained by Radio New Zealand, says the standard insulation upgrade is inadequate for houses in the deep south and they should be given special attention.

Energy Minister Gerry Brownlee said the $347 million scheme, which is subsidising insulation upgrades for about 200,000 homes over four years, was the biggest commitment of its kinds by any government.

He said he was confident the standards were adequate for all homes.