Proposals to decarbonise the country's buildings to help meet climate change targets risk turning some Scots into “mortgage prisoners”, Fergus Ewing has claimed.

The Scottish Government has just finished a consultation on legislation proposed to reduce carbon emissions from homes as well as public and commercial properties.

Its Heat in Buildings Bill includes a plan to compel homebuyers to switch from oil or wood-burning boilers, perhaps two to five years after purchase. It also sets buyers  a deadline to comply with minimum energy-efficiency standards.

But the SNP MSP Mr Ewing, a former secretary for rural affairs, fears homeowners who cannot afford to make the necessary changes could end up unable to sell their property.

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The MSP for Inverness and Nairn told The Sunday Times: “Given these obligations will be unaffordable or unachievable or both, that in turn means that such illegal homes won’t qualify for a new mortgage.

“Those that break the law after purchase may even face existing mortgages being called up.

“The combined effect, according to some banking sources, may cause lenders to increase mortgage lending rates for Scotland as opposed to the rest of the UK.

The Herald: File photo dated 04/06/15 of Fergus Ewing, Minister for Business, Energy and Tourism, who will chair the Scottish steel taskforce which aims to rescue the country's last two major steelworks, as they meet for the first time today. PRESS ASSOCIATIONSNP MSP Fergus Ewing.   Photo PA.

“Higher interest rates for Scots! Imagine if Westminster proposed that. Homes that break the law will become unsaleable, and the owners thus become mortgage prisoners.”

A consultation on the new bill was published in November by the Scottish Greens co-leader Patrick Harvie when his party was still in a power sharing arrangment in Holyrood with the SNP. The consultation ended in March.

Mr Ewing has been an opponent of some of the environmental policies and laws produced during the period of the Bute House Agreement between the two parties including the deposit return scheme and plans to create highly protected marine areas off Scottish coasts. Both of the latter policies have been stalled.

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One of the questions asked in the heat in buildings bill consulation is how long homebuyers should have before they have to bring their property up to clean heating standards.

There have already been suggestions for a series of exemptions for various kinds of homeowners, including people who buy properties, such as certain types of flats, for which clean-heating options are limited.

Buyers, according to consultation documents, will know whether the property they are considering needs to be upgraded. That is because homes with polluting systems will have this spelt out in their mandatory energy performance certificates or EPCs.

The Herald: First Minister John Swinney and Deputy First Minister Kate Forbes arriving at the Barclays Campus in Glasgow where Mr Swinney set out his intention to engage with the business community to boost economic growth.   Photo PA.

Officials and experts have long recognised that decarbonising heating is one of the biggest challenges for reducing Scotland’s dependency on the fossil fuels that generate greenhouse gases.

The Scottish Government has suggested that its bill should become law by the end of the current parliament but that timetables for its introduction and enforcement would be for the next term.

Ariane Burgess MSP, the Scottish Greens housing spokeswoman, said: “Buildings in Scotland account for 20% of our climate emissions, and we’ve seen over recent years the sky-high bills that can result from housing with poor energy efficiency. The status quo simply isn’t sustainable.

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“The Heat in Buildings Bill is a game changer that will be key to dealing with both of these problems. By improving home insulation and hugely expanding the use of clean energy like heat pumps and networks, we can have greener, climate-friendly homes that don’t cost the earth and reduce our dependence on fossil fuels.”

Speaking to the Sunday Times Mr Ewing also took aim at government proposals for further regulation of private rentals.

He said plans to extend a rent freeze for five years, and introduce local authority rent control areas, were “absolutely bonkers”.

The measures were introduced when the Greens were in government.

Mr Ewing, himself a landlord, suggested that such policies would suppress supply just as demand was rising.

“People who, like me, rent out a modest house, will know that the Scottish Government now plan to extend rent controls for up to five years with no rent increases,” he said.

“This would simply speed up the current process of more and more private landlords giving up and selling off their properties.

“How can you possibly make a reasonable return with a rent freeze for five years? Costs rise, but income flatlines. That’s also an incentive for all landlords not to carry out needed repairs or improvements. Houses and flats then degrade.”

Average private rent in Scotland rose by 16.5%, from £813 to £947. In some areas, such as Lothian and Glasgow, the increases were more than 20%. These rises do not affect sitting tenants but some critics have suggested the freeze incentivises landlords to find ways to replace sitting tenants with new people on new rates.

Mr Ewing called on his ally Kate Forbes, the new Deputy First Minister, to hold a series of summits with leaders in property, finance and construction to kick-start more private sector investment in housing.

“The truth is, as anyone in business can testify, key investors in new housing have simply abandoned Scotland over the past three years, because of the unfolding waking nightmare of the green extremists allowed to bring forward an endless succession of lunatic schemes and wheezes.”

In response to his comments, a Scottish Greens spokesperson said: “Last week the politician Fergus Ewing voted to declare a housing emergency in Scotland, including welcoming the Housing Bill that will introduce rent controls.

“Just a few days later and landlord Fergus Ewing has taken to the papers to complain that the very measures being taken to deal with the housing emergency, and keep rents affordable for families across the country, might impact his profits.

“He can’t have it both ways. Does he care more about the crucial work being done to ensure people are financially secure in their homes, or does he care more about his personal income?

“The evidence from the rent freeze introduced during Covid was clear: despite dire warnings from people like Fergus, the housing stock available in the rented sector significantly increased over that period.”

Mr Harvie took to X/Twitter this evening to raise concerns about whether the heat in buildings bill and rent controls would still be advanced by the Scottish Government.

"No surprise that the right wing of the SNP are now targeting both rent control and zero-carbon heating. It's worrying to see not a single comment from Scottish Government in the article defending these policies, which are vital in response to both housing and climate emergencies," he wrote.

The Greens have been fearful that some of the policies - including both rent controls and the decarbonisation of buildings - could be dropped since former First Minister Humza Yousaf ended the Bute House Agreement last month.

Last weekend, the Scottish Government told the Herald on Sunday the minister for climate action Gillian Martin would be meeting the regulatory review group to discuss its advice after the body made criticism of aspects of the heat in buildings bill.

A spokesman said the proposals for the bill drew almost 1,700 responses, which were currently being considered.

He said: “As a result of actions set out by the New Deal for Business Group, a newly established Regulatory Review Group is already engaging with business on a range of policies and provided helpful input. We will continue to engage with them on this and other matters, and Minister for Climate Action Gillian Martin will be meeting with the regulatory review group shortly to discuss its advice.”