The UK has enacted a legally binding target to reduce its carbon emissions to net zero by 2050. To meet this target, carbon emissions resulting from heating homes must be reduced. Insulation decreases the amount of heat lost through roofs, walls, and floors, meaning less energy is required to heat a building. 

The Government runs schemes to encourage the uptake of insulation measures, but installation rates have fallen significantly since 2012. The Committee on Climate Change and the House of Commons Business, Energy and Industrial Strategy Committee have argued that the Government should implement new measures to increase the amount of insulation being installed. 

On 22 June 2020, Lord Teverson will ask the Government about its plans to insulate homes in the UK in order to meet the target for net zero emissions by 2050. 

Why is insulating homes important? 

Net zero target 

The UK has enacted a legally binding target to reduce its carbon emissions by 100% of 1990 levels by 2050. This is known as the net zero target, because the legislation allows the UK to offset any emissions in excess of 1990 levels by purchasing carbon credits. The net zero target replaced the previous target of reducing the UK’s emissions by 80% of 1990 levels by 2050.  

Carbon budgets 

To inform policy and measure progress towards the target, the UK sets five-yearly carbon budgets. A carbon budget places a restriction on the total amount of greenhouse gases the UK can emit. Budgets up to the fifth carbon budget, covering 2028–32, have been set. The fifth carbon budget would limit annual emissions to an average 57% below 1990 levels

Reducing energy use in homes 

Energy use in homes accounts for about 14 percent of UK greenhouse gas emissions, according to the Committee on Climate Change (CCC).  

The majority of energy used in homes, 63%, is for space heating. Insulation reduces the amount of heat lost through walls, roofs and floors, meaning that less energy is required to heat a building.  

The CCC argues that “near-complete” decarbonisation of how we heat our homes would be required for the UK to meet its emission reduction targets. This can be achieved through changing to cleaner fuels and reducing the amount of energy required. 

What is the current state of insulation of the nation’s homes? 

At the end of 2019, 70% of homes with a cavity wall had cavity wall insulation (14.1 million properties), 66% of homes with a loft had loft insulation (16.4 million properties) and 9% of homes with solid walls had solid wall insulation (764,000 properties). 

In 2017, carbon emissions from homes were 9% below 1990 levels. When adjusting for annual temperature variation, emissions from homes rose by 1% in 2017.  

How have insulation rates progressed over time? 

Rates of energy efficiency measures being installed have fallen in recent years. Figure 1 shows the number of insulation measures installed in homes under government schemes between 2008 and 2017. 

Figure 1: Annual installation rates of loft insulation, cavity wall insulation and solid wall insulation under government schemes, 2008–2017

Graph showing rates of insulation installed in homes falling since 2012.

Source: Committee on Climate Change, UK Housing: Fit for the Future?, 21 February 2019, p 29. 

The rate of loft and wall insulation measures going into houses under government schemes is 95% lower than in 2012. Some of the decline is due to a decrease in the availability of low-cost measures, with the remaining potential for energy efficiency interventions becoming more expensive. However, the House of Commons Business, Energy and Industrial Strategy Committee found that there is significant potential for more insulation to be installed that would be cost effective:  

[..] across homes in the UK there is remaining cost-effective potential for around 20 million insulation measures to 2035, and 17 million in England. Installing all of these measures would equate to billions of pounds of energy savings. For England, the 17 million measures is equivalent to around 20,000 insulation improvements being installed every week between now and 2035. 

What programmes and targets does the government have in place? 

Eco and Green Deal 

The energy company obligation (Eco) and green deal are Government energy efficiency schemes, which began in 2013. They replaced the previous energy efficiency schemes: the carbon emissions reduction target, community energy saving programme and warm front. Their aim is to improve the efficiency of the country’s homes by encouraging the uptake of energy efficiency measures through grants, loans, and subsidies.  

The Government has a target to upgrade around one million homes through Eco and other Government domestic energy efficiency schemes. The target covers a five-year period, from the start of May 2015 to the end of April 2020. As of December 2019, around 963,900 homes had at least one improvement measure installed under Eco or the green deal. 

Clean Growth Strategy 

The Clean Growth Strategy sets out the Government’s policies aimed at increasing economic growth and decreasing carbon emissions. The strategy includes measures to bring emissions within those set out in the UK’s fifth carbon budget, covering the period 2028–32. 

In the strategy, the Government says that one “possible pathway” to achieving its emissions reduction goal for 2032 involves emissions from homes falling by almost one fifth compared to 2017 levels. This pathway could see a further six to nine million properties insulated. The Government says that “more broadly, our aspiration is that as many homes as possible are improved to EPC [energy performance certificate] Band C by 2035, where practical, cost-effective and affordable”. 

In its 2019 report on energy efficiency in buildings, the House of Commons Business, Energy and Industrial Strategy Committee criticised the Government for not defining “where practical, cost-effective and affordable” and for not putting in place a measurable target for this ambition.  

What policy recommendations have been made? 

House of Commons Business, Energy and Industrial Strategy Committee 

The House of Commons Business, Energy and Industrial Strategy Committee highlights various factors that hinder the take-up of energy efficiency measures, including: 

  • high upfront costs; 
  • long-term returns;  
  • split incentives between landlords and tenants;  
  • the ‘hassle’ of retrofit works; and  
  • a perception that energy efficiency investment is not captured by property prices. 

It concludes that because of these obstacles, Government should intervene in the following ways: 

  • As fuel poor or low-income households are often not able to pay for energy efficiency measures, these costs should be covered by public investment to a significant or full extent. 
  • A combination of central government funding and social landlord investment should pay for energy efficiency in the social-rented sector. 
  • Better off households and private landlords should, where possible, pay for energy efficiency improvements themselves. However, because not all benefits of energy efficiency are reflected in market prices, incentives and regulation are needed to induce ‘able to pay’ property owners to invest. 

Committee on Climate Change 

The Committee on Climate Change’s scenarios for meeting the fifth carbon budget require insulation of about 7.5 million more walls and lofts from the number recorded in 2015.  

The CCC argues that in many areas current policy is failing to drive uptake of energy efficiency measures in homes, including for highly cost-effective measures such as loft insulation. The CCC states that the uptake of energy efficiency measures such as loft and wall insulation must be increased, and that “policy needs to incentivise efficient long-term investments, rather than piecemeal incremental change”. 

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