Heated debate: Is Scotland's target for decarbonising housing too ambitious?

When Arab oil producers put an embargo on sales following the outbreak of war between Israel and a coalition led by Egypt and Syria in 1973, it was to have profound economic and political implications for the West. The so-called oil shock plunged the British economy into recession and helped usher in the three-day week the following year. In Sweden, the crisis led to a reassessment over energy supply and the gradual adoption of a nascent technology – heat pumps. 

While the idea had been around since the middle of the nineteenth century, the large-scale adoption of heat pumps only began in the latter part of the twentieth. In 1951, a heat pump was installed at London’s Royal Festival Hall, using water extracted from the River Thames.

Caught between the oil crisis on one hand and the domestic campaign against nuclear power on the other, the Swedes began the gradual adoption of heat pumps in the mid-1970s. Today, around half of Swedish homes have one installed, although it is neighbouring Norway that is thought to have the highest penetration of the devices in the world. According to the Regulatory Assistance Project (RAP), an NGO, the heat pumps sold over the last 30 years in Sweden have contributed to a 95 per cent reduction in CO2 emissions from heating.

The success of the technology in Scandinavia also belies the argument that heat pumps don’t work in cold weather. Last year, Labour peer Lord Willie Haughey, the owner of a company which supplies heat pumps, said the units were unsuitable replacements for gas boilers because they can stop working in temperatures of less than -5C or require more electricity to function properly. Patrick Harvie, the Green minister with responsibility for decarbonising heating, later told the entrepreneur to “catch up” with some of his rivals and “invest in a bit of R&D”.

But while the rollout of heat pumps in Scotland and the rest of the UK has been patchy at best, there are nevertheless question marks over whether the technology is the best to help meet the country’s net zero targets. As part of the road map to net zero by 2045, Scotland must reduce its emissions by 75 per cent by 2030 against 1990 baseline levels. To meet that target, around a quarter of heat in buildings will have to be decarbonised. There are particular challenges around replacing gas boilers in tenements, which account for more than a third of homes across Scotland, a figure that rises significantly in the cities.

A report published in November by a short-life working group concluded that decarbonising Scotland’s tenements would “not be an easy task” but was nevertheless imperative if the net zero target is to be met. The group called for a phased approach to regulating tenement buildings and said “very significant financial support” would be required from government to help owners make their heating systems greener. Estimates in the Scottish Government’s Heat in Buildings Strategy put the total cost of decarbonising the country’s housing stock at £33bn. 

One possible glimpse into the future can be found in Govanhill, an area of Glasgow’s south side populated by pre-1919 red sandstone tenements. In Niddrie Road, a building owned by a housing association which sat empty and in need of significant remedial works was retrofitted with a new heating system and improved insulation. The project, which was supported by the Scottish Government and Glasgow City Council, also saw significant building improvements carried out. It’s estimated the work will lead to a 90 per cent reduction in energy usage from heating. But this is just one building comprising eight flats with one owner – the housing association. To do something similar at scale when buildings may have a mixture of owners and either private rental or housing association tenants will be hugely complex. 

“It’s really challenging,” says Ken Gibb, a professor in housing economics at the University of Glasgow and director of the UK Collaborative Centre for Housing Evidence, a research group involved in the Niddrie Road project. “Mixed tenancies make it difficult to have close by close, block by block solutions when you have to negotiate with so many extra parties. 

“Pre-1919 tenements, in particular, are difficult because they are sandstone, they’re old and there are also underlying repair issues, things which only become apparent when you start working. When we did our work in Niddrie Road, the costs were much higher than anticipated. It’s only when you get right down to the detail that you find out what’s critical. When you do a survey, you don’t necessarily look at the quality of the plasterwork or what’s underneath the plasterwork.”

You don’t have to look far to find cautionary tales for how the costs associated with installing new green technologies can quickly spiral. When the Crown Office set about decarbonising the procurator fiscal’s office in Elgin by fitting a heat pump system, the original £2.2m price tag quickly rose to £3.5m – a bill picked up by the taxpayer. Fergus Ewing, the outspoken former SNP minister, called it the “price of having Green ministers in government”. 

Decarbonising housing is just one part of Scotland’s effort to reach net zero, but it is an important part. Emissions from housing account for 13 per cent of the country’s total and the recent spike in energy prices has underlined the economic as well as the environmental imperative of using less gas and electricity to heat our homes.

Yet despite the looming 2030 target, the Climate Change Committee (CCC) has warned that the Scottish Government is falling short of the goals it has set itself. In a stinging rebuke published in late 2022, the CCC warned that Scotland’s emissions targets were “in danger of becoming meaningless” and said the country’s lead over the rest of the UK had been lost. The CCC specifically identified the government’s work on decarbonising buildings, saying the overall 2030 target rested on “rapid action” being made in that sector. “Despite new public funding in this area, policies are still wholly inadequate to deliver the scale of low-carbon heat and energy efficiency improvements required,” it said.

Since that report was published the government has rowed back on its commitment to publish its updated Climate Change Plan. The draft climate change plan, which sets out details of progress towards meeting Scotland’s net zero targets, was due for publication in November. Then net zero secretary Mairi McAllan blamed recent UK Government announcements, saying additional time would be required before the plan could be put before parliament. The CCC described the delay as “very disappointing”. 

Indeed, as we get closer to 2030, the government’s target looks increasingly ambitious if not unachievable. During the recent public consultation on the heat in buildings strategy, academics at the University of Edinburgh highlighted that the implications of the emissions goal is that Scotland is on a faster path to decarbonisation than other European countries. In the Netherlands, for example, 20 per cent of homes are expected to be connected to renewable or low-carbon heating technologies by 2030. The figure for Scotland is 50 per cent. 

The academics wrote: “For the Heat in Buildings Strategy, the key issue is the feasibility of the pathway set out in the consultation document. This pathway is notable for its sheer scale and pace of change, with around half of the Scottish domestic building stock converted to low carbon heat supply in less than a decade, requiring exponential rates of increase in low carbon heat installations year-on-year, starting from a very low base.”

While there’s no doubting the importance of reducing overall carbon emissions, there are arguably more pressing priorities when it comes to housing. Like the rest of the UK, Scotland is currently in the grip of a housing crisis with demand outstripping supply, particularly in rural areas. Figures published last month show homelessness cases are currently at the highest level on record, with official statistics showing there were more than 30,000 live applications between April and September 2023 – up 10 per cent on the same period the previous year. There were also big increases in the numbers living in temporary accommodation with 15,625 households and 9,860 children in such housing – an eight per cent increase on the year before.

“It’s about how you discount the future,” says Gibb. “If you discount the future a lot, then what’s happening now is really important. But there are wider gains from net zero policy – there’s certainly an economic multiplier effect. Greening the economy is very important in the long term and very important for future generations. In the short term, we’re clearly facing major problems with temporary accommodation, with affordability and with affordable housing supply. There are really difficult political choices to be made.” 

From a more or less standing start, Scotland is aiming to become a world leader when it comes to decarbonising its housing stock. It has not had the decades to prepare for the phase out of gas boilers that countries such as Sweden and Norway have had, and its preponderance of tenements makes the task particularly challenging. While there may not be a lack of political will to get the job done, the current pressures on the public finances may yet be the biggest determiner of whether the 2030 goal is achieved.