A GREEENS minister has insisted he does not yet know how much of the £33 billion bill to upgrade heating systems will come from private funds as he stressed he will “cast the net wide” to ensure enough funding is available.

Scotland has committed to become net zero by 2045 – with one of the biggest challenges facing the SNP-Greens government being a strategy to decarbonise heating in buildings, with most homes reliant on fossil fuel boilers.

The Scottish Government has drawn up a strategy for first improving energy efficiency of homes to meet EPC rating C at certain trigger points, with a final backstop for all homes set as 2033. Ministers have set 2030 as a target date for at least one million homes being heated by zero emission technology.

READ MORE: Warning those who can afford it will have to help pay for decarbonising buildings

But Tory MSP, Dean Lockhart, raised the strategy, published by Greens Zero Carbon Buildings Minister Patrick Harvie, that “estimates it will cost £33 billion to retrofit Scotland’s housing stock”.

Speaking at Holyrood, Mr Lockhart asked Mr Harvie to “clarify how this funding will be divided between public sector funding and private sector funding”.

He added: “There’s also a lot of confusion over how much funding will be available for individual households to help them replace existing fossil fuel boilers."

“Can the minister undertake to clarify what financial assistance will be available to individual households to replace their boilers?”

Mr Harvie insisted that “the level of support to individual households in Scotland is higher than that provided by the UK scheme”.

He said: “The UK Government’s boiler upgrade scheme, for example, looks set to offer grants of £5,000 to £6,000 for renewable heat systems.

“But the Home Energy Scotland scheme that the Scottish Government funds gives interest free loans for homeowners with cashback grants of up to £7,500 for zero emission heating – plus up to £6,000 for energy efficiency measures.”

Pointing to the concerns over the proportion of retrofit funding that will be needed from the private sector, Mr Harvie said: “I’m sure he understands that the answer is no.

“I cannot pin down right now and no government would be able to pin down right now exactly what the share of costs will be right through to 2045. That’s why we’re looking to create a green heat finance taskforce – to cast the net wide for a very wide range of measures to ensure the investment necessary is available.

“The only alternative would be for Mr Lockhart to come forward with a a£33 billion tax rise to suggest to us – if he wants the public sector to pay for the lot.”

Last week, the outgoing chair of the Scottish Government’s just transition commission, Jim Skea, told MSPs that that those who can afford it will need to contribute to efforts to decarbonise heating systems.

But Professor Skea insisted that neither the Scottish Government or taxpayers could “afford to step up for the kind of level that is required” to pay for heating systems not reliant on fossil fuels to be installed.