Key terms explained for the Domestic Renewable Heat Incentive

Biomass installations that are first commissioned after scheme launch need to meet the RHI air quality requirements. The air quality requirements set limits on the emissions a biomass installation can produce. Installations affected by these requirements will need to have an RHI Emission Certificate to be eligible for the Domestic RHI scheme. To check whether a biomass product has an RHI Emissions Certificate, search the RHI ECLIST hosted by HETAS (the RHI Emission Certificate listing body). Your installer should be able to help you select a certified biomass product.

In terms of the air quality requirements, you must:

use a fuel type specified on the emissions certificate,

use a fuel that does not exceed the maximum moisture content specified on the certificate, and

operate your heating system in accordance with the manufacturer’s instructions in relation to the control of emissions of particulate matter and oxides of nitrogen. Under the scheme, emissions of particulate matter (PM) must not exceed 30 grams per gigajoule net heat output, and emissions of oxides of nitrogen (NOx) must not exceed 150 grams per gigajoule net heat output.

You will need to follow these rules for the duration of the seven year payment period to remain eligible to receive payments. You will also need to declare that you are meeting the air quality requirements on an annual basis. We may ask you to provide evidence of compliance with these requirements. We strongly recommend keeping all fuel receipts, records of transactions or annual statements of fuel purchased for the entire time (seven years) you’re a member on the Domestic RHI scheme.

For more information on how you can meet the air quality requirements see Section 9 ,Chapter 2 and Section 3 Chapter 3 of the Essential guide.

If your application to the Domestic RHI is approved, you will need to declare each year that you comply with the scheme requirements. Your installer may not fill out your annual declaration for you. This is because you are making declarations about your property and heating system, for which you are responsible.

We’ll send you an email when these are due, (or by post if that’s how you applied) with instructions on how to complete them. To ensure your payments are not suspended, you must submit them within 28 days. Please ensure your contact details are up to date.

For more information about your responsibilities once you become a participant see Chapter 3 of the Essential guide. For a list of the annual declarations and information on how to submit them, see our Help sheet: How to complete and submit your annual declarations.

You can't seek approval for a heating system under both the Domestic and Non-Domestic RHI schemes. 

If your property has previously been heated by a Non-Domestic RHI accredited plant, you can’t apply for accreditation to the Domestic RHI scheme for any installation heating the same property. This also applies if you have submitted an application to the Non-Domestic RHI scheme which has been approved but you have subsequently withdrawn that application. However, if you have been rejected under the Non Domestic RHI scheme, you can apply to the Domestic RHI scheme before scheme closure on midnight at the end of 31st March 2022.  
 

Assignment of rights is an option to help householders and organisations access finance to overcome the upfront cost of a renewable heating system. This option allows an investor to assist in meeting the costs of the installation of a domestic renewable heating system for households and/or organisations. Households and organisations are then able to assign their rights to Domestic RHI payments to “nominated” investors.

Applicants must be the owner of the renewable heating system at the application stage and throughout the Domestic RHI membership. Investors aren’t permitted to own any part of a plant for which they will be nominated to receive payments. Both participants and investors will have to comply with their ongoing obligations and responsibilities if accredited onto the scheme.

For more information, see the Guide to Assignment of Rights.

In joining the scheme, participants agree to be subject to audits to verify their eligibility for the scheme and compliance with their ongoing obligations. We select installations for audit based on various factors, including random sampling. Anyone can be selected for an audit check at any time, and checks can happen multiple times.

If we suspect or discover that you’re not complying with your ongoing obligations, or that your installation was accredited based on incorrect information, we have the right to suspend all or part of your payments while we investigate. Once we have concluded the investigation, you will be informed of our decision and any action that will be taken. If we find that a non-compliance has occurred, depending on its severity, we may withhold all or part of your payments, or revoke your installation’s accreditation.

Audits can take place pre-accreditation and post accreditation. Audits can also be desk based or require site visits.

For more information, see Section 10 of Chapter 3 in the Essential guide.

Sustainability criteria for the Renewable Heat Incentive (RHI) were introduced on 5 October 2015 to ensure all installations using biomass fuels meet the government’s environmental objectives. From midnight at the end of 31 March 2022, government has indicated that they will be including a new wood fuel quality criteria for all biomass wood fuel (except for wood fuel contained in waste).  If you are a Domestic RHI member with a biomass technology, any fuel purchased and received by you must meet these sustainability requirements.

To meet these requirements, you'll need to have been using an approved sustainable fuel from a supplier listed on the Biomass Suppliers List (BSL). The BSL is a list of all registered biomass suppliers that stock one or more of these sustainable fuels. You’ll need to check with the supplier which of their fuels is an ‘approved sustainable fuel’. The sustainable fuels that they supply will have a specific authorisation number. We refer to this as the ‘BSL authorisation number’ which takes the format of: 'BSL-1234567-1234'. It can usually be found near your fuel payment amount on your payment receipt.

You can find BSL fuels here: Biomass Suppliers List.

If you use logs, or other waste wood from your own property as fuel in your biomass boiler, you can register yourself on the BSL register as a self-supplier. If you mainly use wood from your own property, but occasionally buy roundwood (or other raw wood) from another source to process yourself, you can also register on the BSL, but as a ‘producer-trader’. For more on how to register and self-supply classifications, see the next question and view the BSL guidance on supplier types. 

We check the authorisation number as part of your annual declarations and as part of our routine audits so it’s important that this information is recorded. You must keep all of your fuel receipts for your entire membership on the scheme. We can ask for these at any time.

As the landlord and the participant under the Domestic RHI scheme, it’s one of your ongoing obligations to make sure that the fuel used is BSL compliant. If it’s not, or you can’t prove that the fuel was purchased from a BSL registered supplier, then this may affect your RHI payments.

For further information about BSL, please see the BSL guidance. If you have any queries, contact the administrator of the BSL at bslhelpdesk@woodsure.co.uk.

In October 2021, the Government Response to Clean Heat Grant proposals within the ‘Future support for low carbon heat’ consultation named Ofgem as the intended administrator of the Boiler Upgrade Scheme (BUS), formerly known as the Clean Heat Grant.

The BUS will aid the decarbonisation of buildings through providing upfront capital grants to support the installation of heat pumps and biomass boilers in homes and some non-domestic buildings. For more information, please see the webpage for the Boiler Upgrade Scheme.

The commissioning date of your heating system can be found on your MCS certificate.

Your commissioning date is important because it will go towards determining:

• when you can apply to the scheme; and
• the tariff rate that you will receive.

‘Commissioning’ is a technical term and will often be the same as the installation date. However, there is an important difference between the two, and it is the commissioning date that is referred to in the scheme regulations.

The installation date is the date on which the equipment for the heating system was installed.

The commissioning date of the heating system is the date on which any tests and procedures that amount to the usual industry practices for that type of system were completed. These tests will demonstrate that the heating system is operating correctly, generating heat, and that it complies with industry standards. The commissioned date is shown on your MCS certificate. Installers need to issue a certificate for an installation within 14 days of commissioning.

The commissioning date is also the start of the window in which you are able to make an application. You have one year from the commissioning date shown on your MCS certificate to submit an application to us. However, if your installation is commissioned on or after 1 March 2019, you can apply at any time before the scheme closes on midnight at the end of 31 March 2022.

If you submit an application to Ofgem outside of this time period, you will not be eligible for the scheme.

 

Applications submitted for the Domestic RHI on or after 1 April 2016 have their tariffs adjusted in line with the Consumer Prices Index (CPI). The CPI is a measure of inflation and CPI rates are produced annually by the Office for National Statistics (ONS). Tariffs will be adjusted in accordance with CPI on 1 April every year. If you have grant funding that will be deducted from your payments you should be aware that the amount to be deducted will also be subject to CPI adjustment.

Applications submitted for the Domestic RHI before 1 April 2016 have their tariffs adjusted in line with the Retail Price Index (RPI).

 

This key term is relevant to Assignment of Rights, which came into effect on 27 June 2018.

When investor registration is successful, the contract(s) that the investor submitted to us, which is to be used in their agreements with applicants, will be issued with a Contract ID. This number will reference that approved contract on our system.

For more information, see the Guide to Assignment of Rights.

 

A cooker stove is a biomass stove which is capable of generating heat for the purpose of cooking food. The cooker stove must be designed and installed to ensure that heat generated for that purpose is incidental to, and cannot be controlled separately from, any heat generated for the purpose of space heating or domestic hot water heating.

For more information, see Section 3, Chapter 2 of the Essential guide.

Domestic hot water refers to hot water used in an eligible property (eg water taps, shower), which was heated by an accredited Domestic RHI plant. Domestic hot water doesn’t include space heating (including heat dumps) or swimming pool heating.

An Eligible new build must meet the following criteria:

• The property must have been built principally using the labour or resources of the first owner. This means that the first owner of the property must have either physically constructed it or financed its construction. Where the first owner financed the construction of the property, this can be through the use of a custom-build mortgage or loan.
• The first owner and all subsequent owners of the property must be individuals. The property cannot have been owned, wholly or partly, and at any stage, by a person who is not an individual. If you buy an “off-plan” property from a developer, it is unlikely to be eligible, even if you input substantially into the design, including instructing the developer to install renewable heating.
• Must be first occupied on or after the installation was commissioned

If you are replacing an existing heating system in a property, we would class the property as retrofit. This also applies in a new property where an existing heating system was included during the construction.

If you renovated your domestic property significantly (e.g. you stripped the building down to a shell and re-built, or extended the property), it will have been occupied, at some point, before the renewable heating system was commissioned. You will not be able to meet the eligible new build criteria and will need to follow the normal ‘retrofit’ application route.

If your property was converted from a building used for non-residential purposes (e.g. a barn or warehouse) into a dwelling, it will not have been occupied (as a ‘dwelling’) while it was used for non-residential purposes. If your converted property was not occupied before the renewable heating system was installed, you will need to meet the eligible new build criteria.

An Energy Performance Certificate (EPC) is a report that assesses the energy efficiency of a property and recommends specific ways in which the efficiency of your property could be improved. A property will be considered to be an ‘eligible property’ under the scheme if it has been issued an Energy Performance Certificate (EPC) on the basis that it is a dwelling (referred to from this point onwards as a ‘domestic EPC’). 

 If you do not have a copy of an EPC for your property, you may be able to access a copy online, if one already exists. If you are in England or Wales, you can find an EPC here. You can check whether an EPC already exists for a property in Scotland here.

An EPC reference number is required as part of the application process for the Domestic RHI. The EPC is used to:

• determine whether the property can be considered domestic
• evidence that the required loft and cavity wall insulation measures have been installed. 
• determine the heat demand figure used for the payments calculation for non-metered biomass and heat pump applicants.

The heat demand figure is only included in EPCs for dwellings. A non-domestic EPC would not show this figure and therefore could not be used to work out payments using the deeming methodology.

Your EPC must include a heat demand figure and must be less than 24 months old at the date of application. Your EPC needs to accurately reflect information about your house, so if you have undertaken construction work on your property you may need to get a new EPC to ensure it reflects your circumstances. If you get an EPC during construction work, referred to as Predicted Energy Assessments (PEAs), it won’t be able to accurately reflect the final state of the property, so we can’t accept it. We will always ask you for the most recent valid EPC available for your property. 

If your EPC states that either loft or cavity wall insulation are required you must get an assessor to produce a second EPC after installing the insulation to prove that you have done this. Often your EPC assessor will be able to provide this service, however a list of Domestic Energy assessors is available at: Get a new energy certificate - GOV.UK and Energy Performance Certificates - mygov.scot You may be exempt from this requirement, please see Annex 1 in the Essential guide. To find out how we determine payments based on EPCs (if you are not metered for payment), please see Annex 3 and 4 in the Essential guide.

If we have reason to believe that the information on your EPC is incorrect, we may ask you to provide us with a new EPC. Should this occur, we’ll to explain why a new EPC is needed. If we request a new EPC, you must provide this so that we can consider your eligibility for the scheme – refusing to do so will mean that we don’t have all the information required, and we won’t be able to accredit you to the scheme.

For more information about the eligibility criteria, please see Chapter 2 of the Essential Guide.

There are a number of rules surrounding the receipt of grants. Only grants that relate to the purchase or installation of the heating system are relevant for the Domestic RHI. 

If you received a grant from a public source that went towards the cost of purchasing or installing your heating system you will be required to declare the source and amount of funding that you received. If your grant covered the entire cost of purchase and installation, you will not be eligible for the scheme.  The grant amount will be deducted from your payments on a quarterly basis spread over the 7 year participation in the scheme. Grant funding deductions will be adjusted annually in line with changes in Retail Prices Index (RPI) or Consumer Prices Index Consumer Prices Index (CPI). 

For more information, please see Section 7 of Chapter 2 in the Essential guide.

 

The Green Gas Support Scheme (GGSS) is a government environmental scheme that provides financial incentives for new anaerobic digestion biomethane plants to increase the proportion of green gas in the gas grid.The scheme is open to applicants in England, Scotland and Wales for four years from 30 November 2021.

Registered participants will receive quarterly payments over a period of 15 years. Payments are based on the amount of eligible biomethane that a participant injects into the gas grid. For more information please see the webpage for the Green Gas Support Scheme. 

The Domestic RHI scheme rules state that you must install loft and/or cavity wall insulation before applying, if it’s listed as a recommendation on your Energy Performance Certificate (EPC). If it’s not possible, you can still apply for the scheme, if you can provide evidence from a relevant body that one of the following insulation exemptions applies to your property.

Reasons for insulation exemption may include:

• your property is a listed building;
• your property is in a conservation area;
• your property houses a protected species;
• local environmental conditions;
• the structure of your building; and/or,
• it would be otherwise unlawful.

Exempt properties will still need to submit a copy of the EPC.

For more information see Annex 1 of the Essential guide.

 

This key-term is relevant to Assignment of Rights.

To be eligible to join the Domestic RHI and be assigned RHI payments, investors must first apply to become a member of, and agree to the terms and conditions of a Chartered Trading Standards Institute (CTSI) approved consumer code and provide evidence of membership to Ofgem at application for registration. The consumer codes are The Renewable Energy Consumer Code (RECC) the Home Insulation and Energy Systems Contractors Scheme (HIES). 

As part of seeking consumer code membership, investors are required to provide a current copy of the ‘model’ agreement with which they intend to use when entering into assignment agreements with consumers. The consumer codes’ requirements will apply to these contracts, but Ofgem can further assess their suitability before granting registration.

For more information, please see the Guide to Assignment of Rights

 

To be eligible, a renewable heating system must be issued with an MCS certificate by the installer. Certificates can only be issued for systems using an MCS certified product. This shows that the product meets the relevant standards in the regulations.

It is part of your ongoing obligations under the Scheme to notify us if you heating system’s MCS certified product is replaced or repaired. 

For more information, see Section 4 Chapter 2 and Chapter 3 of the Essential guide.

 

Compliance Certificates are effectively checklists which confirm that your heating system was installed according to MCS standards and records key information about the heating system. Your installer should ensure that you are provided with a copy of your Compliance Certificate.

We will not require you to submit a copy of your Compliance Certificate as part of your application. 

A Metering and Monitoring Service Package (MMSP) is a set of meters you can install to collect data about your installation. You can use this data to monitor and optimise its performance. This is an optional metering package.

MMSPs are exclusive to the Domestic RHI and participants who have MMSP receive extra payments if they allow the government to access the data that the MMSP collects. This data may be used to gain valuable insights into the performance of renewable installations and to aid in future policy design.

MMSP is only available for heat pumps, or biomass boilers that burn wood pellets (not biomass pellet stoves or any other biomass boilers). If your membership with the Domestic RHI is terminated, your MMSP registration will also end.

The packages are available on a first-come, first-served basis. There are 11,255 MMSP packages available in total. We publish the data quarterly on our website. For more information regarding eligibility, please see Section 11, Chapter 2 of the Essential Guide. For full information regarding MMSP, please see Chapter 4 of the Guide to Metering.

If your home is not regularly or exclusively heated by your renewable installation, your installation may need to be metered for us to work out your payments. Meters must be installed to accurately measure the heat your installation generates – this is called a ‘metering for payment calculation’ and you will need to submit meter readings every three months. Metering for payment only applies for biomass plants and heat pumps. Solar thermal for heating domestic hot water never has to be metered for payment

 If your heating system is metered for payment, you’ll receive quarterly scheme payments based on the amount of renewable heat your system produces, up to the annual heat demand on your EPC or the relevant heat demand limit – whichever is lower. For applicants, it may be the case that you need to install meters to join the scheme. For participants, if certain circumstances change while your installation is accredited, you may need to fit metering for payment to carry on receiving payments. Once you are required to install metering for payment, you cannot return to being deemed for payment.

The closure of the scheme does not change the requirement for you to install metering if it is required. The important thing to know is that whether a heating system must be metered is not a choice but depends on specific circumstances.

Please see Section 10 Chapter 2 in the Essential guide for further information regarding the eligibility requirements to install metering. If you are a participant, please also see Chapter 3 in the Essential guide for information regarding your ongoing obligations and metering requirements to ensure you continue to be eligible to the DRHI. For further detailed information regarding metering for payment, including how to install metering, submitting metering readings and payments, please see Chapter 3 ‘Metering for payment’ and the Annex in the Guide for Metering. 

This information only applies if you have a heat pump.

After 22 May 2018, all new Domestic RHI applications for heat pumps are required to have an electricity meter arrangement that measures the electricity consumed by it to generate heat.

To receive Domestic RHI payments, you must ensure your meters are properly calibrated, installed and in good working order.

The metering for performance requirement is aimed at making the measurement of performance of the heating systems possible. It’s separate from, and different to, any requirement to be metered for Domestic RHI payments. Unless you are also required to have meters for payment, Domestic RHI payments will still be based on the heat demand listed on your Energy Performance Certificate (EPC), up to the relevant heat demand limit.

You won’t be required to submit electricity meter readings to us unless you have meters for payment. However, The Department for Energy Security and Net Zero recommends you monitor the electricity (kWh) your heating system uses on a regular basis and speak to your MCS installer if your heat pump isn’t performing as efficiently as you’d expect.

If you commissioned your plant before these changes came into effect but applied to the scheme after, you’ll need an MCS installer to install electricity meters before you can make an application to the Domestic RHI scheme.

To comply with this requirement, your MCS installer needs to install at least one of the eligible electricity meter arrangements. For full details and examples, see Chapter 2 ‘Metering for performance’ and the Annex in the Guide to Metering.

There are a number of circumstances where you may be able to install multiple products and apply for these in one application. These scenarios have been outlined below. You will not be able to make separate applications for two products at the same property, unless one of the products is a solar thermal system. You may be allowed to make a single application for multiple products if they are the same technology and have been commissioned at the same time (see key term ‘Commissioning’ for further information on what 'commissioned' means).

We will ask you to send through all related MCS certificates as evidence. If your products were commissioned at different times, or are different technologies, you will need to choose which product to apply for. You will also be required to be metered for payment. For more information, please see the guide to metering.

Someone nominated to act on the organisation's behalf for the RHI. See letter of Authorisation in key terms.

When an applicant intends to enter into an assignment of rights agreement with a Registered Investor, as long as an applicant meets all other scheme eligibility criteria, they can assign their RHI payments to one of the Registered Investors. This means that participants will not receive any RHI payments. Please note that only RHI payments can be assigned; participants cannot assign their Metering and Monitoring Service Package (MMSP) payments.

During the application process, the applicant has the option to assign their RHI payments to a Registered Investor. At the point of accreditation the investor becomes the “Nominated Registered Investor”. Following accreditation of the plant RHI payments will be made directly to the Nominated Registered Investor.

Nominated Registered Investors have ongoing obligations to fulfil in order to continue to keep their registered status, as well as remain a Nominated Registered Investor under the Domestic RHI Scheme.

Please see the Guide to Assignment of Rights for further details

If your application is approved, you’ll become a participant on the Domestic RHI. Throughout the whole time your installation is accredited to the scheme, you’ll have various responsibilities in relation to you, your property, and your installation. These are called ‘ongoing obligations’ and you’ll need to comply with all of them to continue to receive payments and avoid any enforcement action, such as the withholding of payments and recovery of any overpayments. Investors will also have ongoing obligations. For more information, please see Chapter 3 of the Essential guide.

The Letter of Authorisation confirms that you are able to apply on behalf of the organisation, and therefore the person filling out the template must be a signatory on the company bank account. They can use the letter to nominate themselves or another individual to act as the authorised representative if required (if they are nominating another individual, this person is not required to be a signatory on the bank account).

For more information, please see Section 13 Chapter 2 of the Essential guide.

A participant of the scheme means the owner of an accredited domestic plant. Where there is more than one owner, the owner who has provided the required evidence that they have authority to act on the behalf of all the owners.

This key-term is relevant to Assignment of Rights, which came into effect on 27 June 2018.

Once investors are a member of the consumer codes, they can apply to become a Registered Investor under the Domestic RHI. Investors aren’t permitted to own any part of a plant for which they will be nominated to receive RHI payments.

If we have any reason to believe that an investor will not comply with any of their ongoing obligations – such as complying with the terms of the consumer code of practice – we may reject the investor’s application.

Registered Investors have ongoing obligations to fulfil in order to continue be Registered Investors.

For more information, see the Guide to Assignment of Rights.

Applications submitted for the Domestic RHI before 1 April 2016 have their tariffs adjusted in line with the Retail Prices Index (RPI). The RPI is a measure of inflation and RPI rates are produced annually by the Office for National Statistics (ONS). Tariffs will be adjusted in accordance with RPI on 1 April every year. If you have that will be deducted from your payments you should be aware that the amount to be deducted will also be subject to RPI adjustment.

Applications submitted for the Domestic RHI on or after 1 April 2016 have their tariffs adjusted in line with the Consumer Prices Index (CPI).

 

The Right of Review applies for any formal decisions that we make including if we have rejected your application, or if your application was accredited, but we have subsequently made the decision to withhold payments or revoke your accreditation.

To exercise your right of review, you must apply for it in writing within 28 days of receiving notice of the decision which you are appealing, specifying the grounds on which you are requesting it

For more information, please see Section 10, Chapter 3 of the Essential Guide.

The Department for Energy Security and Net Zero is required to keep the operation of the Domestic RHI scheme under review. To evaluate the scheme, they may select specific heating systems to be monitored.

If your heating system is selected for review and evaluation, The Department for Energy Security and Net Zero will write to you to let you know. In order to carry out a review, they may request entry to your property in order to:

• inspect the heating system or any associated metering
• install metering (if selected for monitoring and evaluation. This won’t affect your RHI payments)
• carry out meter readings or download metering information
• check, repair or replace any metering equipment.

The Department for Energy Security and Net Zero may request you to assist in maintaining and reading meters, to keep records, and to provide information relating to the heating system held by you or your installer on request.

If your heating system is selected for scheme review and evaluation you will need to ensure that you comply with any request from The Department for Energy Security and Net Zero relating to the above in order to be able to continue to receive payments.

If you had a heat pump installed before scheme and are a ‘legacy applicant’ you will automatically be assigned a Seasonal Performance Factor (SPF) of 2.5 (the lowest SPF value allowed – for more information, see Seasonal Performance Factor (SPF). This is because an SPF calculated using the MCS guidance was not included in the calculations by your installer.

If you think your heat pump is likely to be more efficient and achieve a higher SPF value, then you can arrange for an MCS installer (this does not have to be the same installer who originally installed your heat pump) to conduct an assessment of your property and issue a new SPF figure using the Heat Pump SPF calculation template for Legacy applicants, which is based on MCS guidance. If you choose to have your heat pump assessed to obtain a new SPF, you will need to provide a copy of the Heat Pump SPF calculation template filled out by your installer. You must have the reassessment done before you apply, as it's not possible to have your heat pump SPF value changed after you’ve joined. The template should be sent to us after you have applied, so that we can check it against your application number.

Space heating refers to heating rooms in a property. Space heating must be delivered using a liquid medium. The heat is delivered to the property through heat emitters, such as radiators or underfloor heating.

This key-term is relevant to Assignment of Rights, which came into effect on 27 June 2018.

When investor registration is successful, we will issue the registered investor with a URIR. This will be used to identify them on our system as a registered investor and link them to any accredited renewable heating systems for which they have been nominated to receive RHI payments.

Registered investors must provide their URIR to applicants in order for RHI payments to be assigned to them.

For more information, please see the Guide to Assignment of Rights.