The initiative came into effect yesterday and provides between 33% and 60% of the total cost of installing insulation and clean, efficient heating in houses built before 2000.
However, Craig Scoullar Electrical insulation co-contractor Bruce Ritchie said there would be an eight-week wait for homeowners wanting to take up the Government's funding offer, and that could continue to grow as more people took up the programme.
"Insulation suppliers are snowed under right now.
Throughout the country, there's a shortage of insulation supply because there's a few [suppliers] around that have contracts for the various government bodies, like Housing New Zealand.
"So they have to finish those contracts first. They're not expected to be finished until the end of July. Then we can hopefully get them to start supplying us with insulation."
Mr Ritchie was concerned about the delays because they had the potential to cause difficult relationships with his customers.
"It's a bit of a pain when you talk to people and tell them there's going to be a delay. And if the supplies still don't come through, we'll have to tell them there's going to be further delays."
Pink Batts Insulation general manager Tony Te Au said he had heard there were delays in supply from many insulation manufacturers, but Pink Batts was working around the clock in its Auckland plant to keep up with demand and was looking to expand production in another plant.
At the moment, Pink Batts only had a two-day delay in supplying insulation to providers.
However, Mr Te Au expected delays to increase as demand for the programme grew.
"I think, inevitably, there will be delays as the industry builds capacity from a product supply and installation capability point of view."
Craig Scoullar Electrical co-owner Becky Scoullar said the phones had been ringing red hot since the Government began advertising the programme two weeks ago.
Up to 10 calls an hour had been coming in for the past week from Otago residents wanting their houses to be assessed, she said.
Staff were fully booked until Wednesday next week completing assessments, but Mrs Scoullar said that was to be expected.
"We're not doing too bad. It's too early to say what long-term demand for installations will be like at this stage. If demand gets too high, we'll look to take on more staff," she said.
Heat Smart funding:
• All eligible houses: 33% of the total cost up to $1300 (incl GST) for insulation, and $500 (incl GST) for clean heating.
• Homeowners with a Community Services Card: 60% of the total cost of insulation and $1200 (incl GST) for clean heating.
• Landlords with tenants who hold Community Services Cards: 60% of the total cost of insulation and $500 (incl GST) for clean heating.
• The funding can be used to install ceiling and underfloor insulation (up to a required standard); a heating device in the primary living space (if the present device does not meet Government standards); and other energy-efficiency measures such as hot water cylinder wraps, pipe lagging, draught-stopping and ground-moisture barriers.
• Providers: AirLana-Terra Lana/AirCon (Christchurch), Be Snug (Auckland), CozyCool Consortium (Porirua), Craig Scoullar Electrical (Concord, Dunedin), Davies Heat `n' Cool (Kaikorai Valley, Dunedin), EnergySmart Ltd (Lower Hutt), Premier Insulation (Auckland).