OFFICIALS have warned almost £11 billion of funding will be needed to transform homes across the Glasgow City Region into energy efficient properties – even before gas boilers are ripped out of homes to meet net zero targets.

The "astounding costs" would mean up to £600 million of investment would be needed each year over the next 15 years to reach Energy Performance Certificate (EPC) level C.

The Scottish Government has pledged for all homes to upgraded to EPC band C by 2035, but only if it is “technically feasible and cost-effective” – with the latest figures throwing that strategy into doubt.

A new report from Glasgow City Region officials suggests that 428,000 properties will need to be upgraded – currently below the EPC band C standards.

The document, to be considered by the Glasgow City Region cabinet next week, has warned the total costs are “estimated to be in the region of £10.7 billion”.

The Scottish Conservatives have called on the SNP Government to set out funding for homes to be upgraded - warning "action needs to happen now, not years down the line".

Plans were unveiled last week for a staggering £30 billion of investment needed to help Glasgow achieve its net zero ambitions.

The retrofit programme as part of the £30 billion ‘greenprint’ for Glasgow hopes to “achieve net zero carbon emissions, give greater energy security, lower household energy bills, warmer homes and better health outcomes through reduced fuel poverty”.

Leader of the city council, Susan Aitken, warned that “levels of investment never seen before in local government” will be needed.

She added: “Our net zero future is about safer communities, warm and efficient homes, sustainable jobs and a prosperous economy.

“Transition has to be about the social and economic well-being of Glasgow and its people.”

City region documents add : “A programme of investment on this scale will be the most comprehensive and ambitious home energy retrofit programme ever to have been undertaken and requires sustained long-term investment.

“Over a 10-year programme of investment and delivery, it is estimated that the programme would support over 75,000 job and generate £4.4 billion in gross value added (GVA) across the Glasgow City Region.

“In addition to the employment and economic benefits, widespread insulation across the region would remove 10.7 million tonnes of carbon emissions per annum.”

City region officials have pointed to “working with owner occupiers” as one of the “most significant risks” to delivering the upgrades.

Of the 428,000 properties in the Glasgow region in need of upgrades, 71% are owned privately by the occupier and 12% are under the control of private landlords.

The report adds: “Overcoming the range of barriers to upscaling retrofit with owner occupiers will require a comprehensive framework of incentives and/or regulation being in place.”

Glasgow’s iconic tenement blocks in particular are understood to be lacking in energy efficiency.

Consultants have recommended local authorities should approach the Scottish Government about getting long term funding for housing association and council homes to undergo a retrofit.

The SNP-Greens' Programme for Government pledged to “provide at least £1.8 billion" to "make our homes easier and greener to hear and progress our commitment to decarbonise 1 million homes by 2030”.

A draft heat in buildings strategy published by SNP ministers earlier this year warns that “transformation of our buildings and energy markets at the scale and pace required is unprecedented”.

The government’s blueprint adds that in order to cut Scotland’s emissions by 75% of 1990 levels in just nine years’ time, as legally committed to do, more than 1 million homes and around 50,000 commercial buildings will need to “convert to using zero or low emissions heating systems”.

The government document adds: “We want our homes to be as energy efficient as possible, meeting a minimum standard equivalent to EPC C at least, where technically feasible and cost-effective, by 2035.

“There will be some circumstances where this is not possible. In such cases, we would expect these properties to achieve the highest standard possible, installing those measures recommended by the EPC assessment as being technically feasible and cost-effective for that building.”

Research published by Citizens Advice Scotland in 2019 warned that “irrespective of who pays”, it was estimated that “the total investment required to bring the energy performance of homes in Scotland up to at least EPC C in the 20 years to 2040 is in the region of £11.1 billion”.

It added: “This is in contrast with the Scottish Government’s cost estimate of £8 billion for domestic properties . Our estimate would amount to £555 million per year.”

Scottish Conservative net zero, energy and transport spokesperson, Liam Kerr, said: "It is clear that the SNP have not outlined what funding is going to be in place to support owners and private landlords to achieve environmental targets.

"Action needs to happen now, not years down the line. These costs are astounding and this is just in one local authority.

"The SNP-Green Government must be upfront about their plans otherwise it is hardworking people who are going to pay the price, if we don't have a fair transition to net zero."

In response to a written question by Mr Kerr asking how much ministers estimate it will cost for a “typical hard-to-treat off-gas grid home” to upgrade to EPC band C by 2050, SNP Net Zero, Energy and Transport Secretary, Michael Matheson, said it could cost up to £17,000 per property.

He said: “Although there is no fixed definition of what a hard to treat home is, we estimate that the average cost of upgrading an off-gas grid property with an initial EPC rating between Band E and Band G to an EPC Band C could be in the region of £17,000.

“As set out in our draft heat in buildings strategy, the cost for an individual dwelling can differ from this average depending on the building type, materials, existing levels of energy efficiency and type of heating systems being replaced.”

Mr Matheson added: “Through the Home Energy Scotland (HES) loan and cashback scheme, we provide interest-free loans of up to £15,000 with an additional 40% cashback up to a total value of £6,000, for homeowners to install energy efficiency measures in order to improve the EPC rating of their property.

“Some owner-occupiers may also be eligible for support via our fully-funded energy efficiency/fuel poverty schemes – Warmer Homes Scotland or the local authority area-based Schemes.

“All these Scottish Government-funded advice and support schemes can be accessed through Home Energy Scotland, run by the Energy Saving Trust.”