"For gaps under doors, you can fit draught excluders - or for external doors, spring-loaded automatic seals."
Older houses often have unused fireplaces that let in the cold air. Mr Hoerning suggests blocking the chimney with a plastic bag filled with shredded newspaper - but make sure it's very obvious so no one tries to light a fire.
Gaps around electrical wiring and plumbing passages are also common, he says.
"Seal gaps using silicone sealants [for smaller gaps] or polyurethane foam [for bigger gaps].
"These passages are often hidden so don't forget to look behind kitchen and bathroom cabinetry and inside wardrobes and hot water cupboards."
Mr Hoerning says households should prioritise keeping their homes warm and dry because cold, damp homes increase the risk of respiratory illness.
Insulation is the most effective way of making your house easier to heat and healthier and low-income households at high health risk may be eligible for free insulation through Warm Up New Zealand: Healthy Homes, Mr Hoerning says.
Households that don't qualify for free insulation may be able to add the cost to their rates or mortgage - costing from about $9 a week, Mr Hoerning says.
"A heater will do a much better job of warming an insulated, dry and draught-free house," he says.
EECA also recommends people shop around to make sure they are getting the best deal on their power.
To compare your options, check out whatsmynumber.org.nz or, for more information visit energywise.govt.nz.
