Heat in buildings monitoring and evaluation Framework

2. Outcomes

2.1 Outcome: reduced energy demand to buildings

2.1.1 Method: ensuring a good level of energy efficiency in domestic properties

Proposed indicator: share of domestic properties achieving a good level of energy efficiency (equivalent to Energy Performance Certificate (EPC) C or better):

• share of owner-occupier properties
• share of private rented sector properties
• share of social rented sector properties

Data source: Scottish Housing Condition Survey (SHCS)

Unit: per cent

Description:

• Achieving a good standard of energy efficiency across Scotland's buildings will play an important part in reducing emissions from our buildings, saving on energy bills and reducing fuel poverty.
• We will track the share of properties meeting an EPC C equivalent or better, using data from the SHCS. Where possible we will report progress for specific population demographics or household groups, for example those living in rural and urban settings, different tenures, different household make-ups (e.g. single-person, families), and by household income level.
• In the Heat in Buildings Strategy and in our consultation on proposals for EPC reform, we have been clear that we consider a good level of energy efficiency to be equivalent to EPC C or better. We recently consulted upon proposals for reforming EPCs and their metrics^[11]. Following analysis of the consultation responses, we plan to respond to the consultation and lay revised EPC regulations to implement the proposed reforms, during 2024. Any changes to the EPC system following this consultation will be reflected in the way we report progress against this Framework.
• Alongside this publication, we are consulting on proposals for a Heat in Buildings Bill, which will seek views on our introducing a minimum energy efficiency standard for privately rented and owner-occupied homes to achieve a good level of energy efficiency. We plan to report annually on the share of homes that meet this standard, subject to the consultation and its future introduction.
• We are also consulting on a similar heat and energy efficiency standard for the social housing sector and will aim to include progress against this standard as part of this Framework.
• We have not included an indicator to monitor energy efficiency improvements in the non-domestic sector since there is currently no reliable data source available, and we do not plan to regulate non-domestic energy efficiency.

2.2 Outcome: increased supply of clean heat to buildings

2.2.1 Method: uptake of low emissions heating and clean heating in domestic properties

Proposed indicator: number of domestic properties currently with clean heating systems:

• heat pumps
• connected to a heat network
• other electric heating

Data source - heat pumps and electric heating: SHCS

Data source - heat networks: Heat Networks Metering and Billing Regulations data and SHCS

Unit: number of domestic properties

Description:

• We plan to report annually on the number of existing homes with clean heating systems^[12] installed in Scotland, such as heat pumps (air source and ground source heat pumps), heat networks (communal heat pumps in a building or connections to district heating), as well as other electric heating (electric boilers and modern, efficient electric storage heaters).
• We will use SHCS to track the number of properties with heat pumps and electric heating installed. Where possible we will also include demographic data. Any year-on-year increases in the number of homes with these technologies installed will also include new builds since the SHCS survey covers the entire housing stock. As described in Annex A, all survey figures are estimates and, in general, the smaller the sample size, the greater the likelihood that the estimate could be misleading, so we will take care when using smaller subsets of the survey sample for analysis.
• We will use Heat Networks Metering and Billing Regulations data to track the number of domestic properties (both occupied and unoccupied). However, these data are only available every four years and compliance is an issue in practice. We may also use alternative data sources, such as SHCS, if such sources can provide additional context to our findings.

Proposed indicator: number of domestic properties recently installing a clean heating system:

• heat pumps (over the last year)
• heat network connections (over the last four years)
• other electric heating (over the last year)

Data source - heat pumps: Microgeneration Certification Scheme (MCS)

Data source - heat networks: Heat Networks Metering and Billing Regulations data

Data source - other electric heating: no data source currently

Unit: number of properties

Description:

• We plan to report on the number of homes with recent installations of clean heating systems. This indicator will allow us to see changes in the rate of installations over time, not just the total housing stock converted to clean heating systems measured by the previous indicator.
• We will use MCS data to report on the number of installations of heat pumps over the last 12 months. While MCS data provide a good approximation of annual domestic installations, these data do not cover non-accredited MCS installations, may include some new build as well as some small scale non-domestic installations, and do not account for heat pumps that have been decommissioned.
• The MCS data do not currently enable us to determine the types of heating systems that heat pumps are displacing, but we will continue to engage with key stakeholders, including MCS and the UK Government to see how we can improve this.
• We do not currently have a reliable data source for the number of other electric heating systems installed each year as these systems are not covered by a certification scheme such as MCS for heat pumps. If data become available in future, we will report this here.
• For new connections to a heat network, we will use Heat Networks Metering and Billing data collected through UK regulations. However, as described above, there are limitations with this data source. As appropriate, we plan to use data from new UK or Scottish regulations in the future.
• We are committed to working with key stakeholders, such as UK Government and Ofgem, the new heat network regulator, to understand the data they will require and collect under proposed consumer protection regulations on heat networks and will seek to increase the availability of such data.

Proposed indicator: number of domestic properties with low emission or low emission ready heating systems, such as:

• biomass boilers
• combined heat and power (CHP)
• fuel cells
• hybrid heat pumps
• hydrogen-ready boilers

Data source - biomass boilers, CHP: SHCS

Data source - fuel cells, hybrid heat pumps and hydrogen-ready boilers: not currently covered by SHCS but could in future if these systems become more prevalent.

Unit: number of properties

Description:

• We will report on the number of low emission and low emission ready heating systems installed in Scotland currently.
• While biomass and hydrogen combustion offer significant emissions savings compared to fossil fuel-based heating, they still produce varying levels of direct emissions. We expect that technologies such as bioenergy may play a limited role in niche circumstances. We also do not consider that hydrogen will play a central role in the overall decarbonisation of domestic heat. We will however continue to monitor the prevalence of these systems, where possible, using SHCS data.
• The SHCS data do not currently record all low emission or low emission ready heating systems, but it may be possible to do so in the future. The data limitations described above relating to the use of small sample sizes in the SHCS are also relevant to this indicator.
• We will continue to review the list of clean and low emissions heating technologies we are monitoring, so that others can be added in future.

Proposed indicator: percentage of new domestic properties with clean heating system completed in the last year:

• with heat pumps
• connected to a heat network
• with other electric heating

Data source: EPC register

Unit: per cent

Description:

• We plan to report on the types of heating systems going into new build properties annually. From 1 April 2024, each new building will need to have a building warrant stating it will be constructed with a clean heating system.
• Our regulations will allow a wide range of suitable clean heating systems, including air source and ground source heat pumps, electric boilers, smart electrical storage heaters, communal heat pumps and connections to heat networks.
• We aim to use EPC register data to track the types of heating systems installed in new properties.

2.2.2 Method: uptake of low emissions heating and clean heating in non-domestic properties

Proposed indicator: number of non-domestic properties currently with clean heating systems:

• heat pumps
• connected to a heat network
• other electric heating

Data source - heat networks: Heat Networks Metering and Billing Regulations data

Data source - heat pumps and other electric heating: Non-Domestic Analytics (NDA)

Unit: number of properties

Description:

• We plan to report annually on the number of non-domestic properties with clean heat. Our current estimate is that just over a half of such buildings use a clean heating system.
• Data for non-domestic properties are limited to NDA which models the entire non-domestic sector based on information from the EPC Register. However, only 17% of non-domestic buildings have an EPC associated with them, so data we model about the sector as a whole should be treated with care.
• We are exploring options to fill this data gap, including working with key stakeholders to develop and enhance data sources. The UK Government is looking to develop a National Buildings Database in England, Scotland and Wales that is expected to include the non-domestic stock, and we are obtaining Building Assessment Reports from public sector bodies under the Heat Networks (Scotland) Act 2021.

Proposed indicator: number of non-domestic properties recently installing a clean heating system:

• heat pumps (over the last year)
• heat network connections (over the last four years)
• other electric heating (over the last year)

Data source - heat pumps and direct electric heating: no data source currently

Data source - heat networks: Heat Networks Metering and Billing Regulations data

Unit: number of properties

Description:

• We also want to be able to track the number of non-domestic properties that have recently installed a clean heating system in order to gauge recent progress. As with domestic properties, this indicator will allow us to see changes in the rate of installations over time, not just the total non-domestic stock converted to clean heating systems measured by the previous indicator.

• While we can use Heat Networks Metering and Billing Regulations data to monitor new heat network connections within the last four years, we do not currently have access to reliable data on recent installations of heat pumps and other electric heating in the non-domestic sector. We will continue to explore potential data sources to help fill this gap.

Proposed indicator: number of non-domestic buildings currently with low emission or low emission ready heating, such as:

• biomass boilers
• CHP
• fuel cells
• hybrid heat pumps
• hydrogen-ready boilers

Data source - biomass boilers and CHP: NDA

Data source - hybrid heat pumps, fuel cells and hydrogen-ready boilers: no data source currently

Unit: number of properties

Description:

• As with the domestic sector, while we do not expect low emission or low emission ready heating systems to be the main solutions to decarbonise Scotland's heating, we recognise that some low carbon technologies may have a limited role to play in niche circumstances. Similarly, we will keep the list of clean and low carbon heating systems under review.
• As outlined above, we do not currently have a suitable data source to be able to track this information in the non-domestic sector, but we are exploring ways to measure progress against this metric.

Proposed indicator: percentage of new non-domestic properties with clean heat completed in the last year:

• with heat pumps
• connected to a heat network

Data source: non-domestic EPC register

Unit: number of properties

Description:

• We plan to report on the types of heating systems installed in new build non-domestic properties annually. As in the domestic sector, all building warrants for new non-domestic properties will need to state that the property will be constructed with a clean heating system from 1 April 2024.
• We aim to use the non-domestic EPC register to track the types of heating systems installed in new properties.

2.2.3 Method: rollout of zero emissions heat networks

Proposed indicator: heat supplied by heat networks (statutory target to reach 2.6 Terawatt hours (TWh) by 2027 and 6 TWh by 2030)to:

• domestic properties
• non-domestic properties

Data source: Heat Networks Metering and Billing Regulations data

Unit: TWh

Description:

• The Heat Networks (Scotland) Act 2021 sets ambitious targets for the amount of thermal energy (heat and cooling) to be supplied by heat networks. These are 2.6 TWh of output by 2027 and 6 TWh of output by 2030. These figures are equivalent to 3% and 8% respectively of current non-electrical heat consumption.
• A draft Scottish Statutory Instrument was laid on 25 September 2023 to set a further target for heat network deployment of 7 TWh by 2035, which would be equivalent to 9% of non-electrical heat consumption.
• We therefore want to measure the heat supplied by heat networks to both domestic and non-domestic properties in order to measure progress against these statutory obligations. While we will use Heat Networks Metering and Billing Regulations data to do this, the data is only available every four years and separating out domestic from non-domestic supply requires us to make assumptions.
• We plan to use data from new UK or Scottish regulations as appropriate, and when possible.

Proposed indicator: share of low carbon heat in existing networks

Data source: Heat Networks Metering and Billing Regulations data (share of fuel source and technology)

Unit: per cent

Description:

• We committed in our Heat Networks Delivery Plan^[13] to finding a way for existing heat networks to develop Decarbonisation Plans to cover both efficiency improvements and replacement of heat sources where these are not already low and zero emission.
• While we do not currently have access to reliable data on the share of low carbon heat in existing networks, we can report on the share of fuel and technology using Heat Networks Metering and Billing Regulations data. However, it is limited in that it assumes networks use only one source.
• We are exploring options to improve data to report against this indicator, including working with other stakeholders, such as the UK Government and Ofgem.

2.3 Outcome: the heat transition is fair, leaving no one behind

2.3.1 Method: heat is affordable

Proposed indicator: percentage of homes in fuel poverty (statutory target in 2040 no more than 5% of households are fuel poor with <1% in extreme fuel poverty)

Data source: SHCS

Unit: per cent

Description:

• As set out in our Heat in Buildings Strategy, it is critical that, as we take action to reduce emissions from Scotland's homes, we do so in a way that supports a just transition and the reduction of fuel poverty. Our ambitious statutory fuel poverty targets require that in 2040 no more than 5% of households are fuel poor, no more than 1% are in extreme fuel poverty and the fuel poverty gap is no more than £250 (in 2015 prices). We also have interim targets for 2030 and 2035.
• We currently estimate the share of Scottish homes in fuel poverty via the Scottish Government's annual SHCS. However, we recognise that the drivers of fuel poverty are complex and inter-linking, and not all within the scope of the Heat in Buildings Strategy Framework. Our Fuel Poverty Strategy^[14] set out four main drivers of fuel poverty that we are seeking to tackle: poor energy efficiency, high energy prices, low household income and how energy is used in the home.
• In line with the Fuel Poverty Act 2019, we consulted the Scottish Fuel Poverty Advisory Panel^[15] on next steps for our strategy and we are engaging with the Panel on its published recommendations^[16], while ensuring that they align with the Heat in Buildings Strategy and other key policies that support delivery of our 2040 statutory fuel poverty targets.
• We will also explore how additional metrics may help to monitor the impact of the Heat in Buildings Programme on fuel poverty, collaborating with the Scottish Fuel Poverty Advisory Panel and other key stakeholders. We are also considering how to measure the impact of heat affordability on non-domestic consumers.
• The Draft Energy Strategy and Just Transition Plan^[17] describes work to inform a monitoring and evaluation framework for a just transition in Scotland, incorporating an evidence assessment of just transition monitoring internationally. We will engage with stakeholders to build on the findings of this research in 2024 and to develop a framework that reflects the Just Transition Commission's recommendations.
• The overarching Just Transition Monitoring and Evaluation Framework will inform the development of the draft monitoring and evaluation framework for each Just Transition Plan.

2.3.2 Method: green heat jobs for the heat transition

Proposed indicator: net change in heat and energy efficiency jobs

Data source: available data insufficient for monitoring

Unit: net change

Description:

• We need to see growth in the number of reliable and skilled tradespeople and businesses who can advise upon and install clean heating systems and energy efficiency measures, as well as monitor potential job losses in more traditional sectors as a consequence of the heat transition. Measuring the net change in heat and energy efficiency jobs will, however, depend on data availability.
• The Office for National Statistics' Low Carbon and Renewable Energy Economy (LCREE) provides annual estimates of the number of full-time equivalents (FTEs) across sectors including renewable heat, renewable CHP, energy efficient lighting and energy efficient products. LCREE also provides data at the 'low carbon heat' grouping. However, these data are insufficient for monitoring purposes due to the wide confidence intervals around the estimates.
• Tracking or developing additional indicators as the supply chain grows will be important for monitoring progress against this indicator.
• We are working to establish reliable measures and indicators related to green heat jobs. For example, we are exploring indicators to track progress in skills and supply chain as part of the monitoring of the Built Environment and Construction Just Transition Plan. This includes research to analyse Scotland's net zero and climate adapted economy, with renewable heat as one of the sectors in focus, as well as monitoring the types of jobs created (for example manufacturing, installation), and the quality of jobs created (for example taking into account pay and representation in the sector).