Using an EPC and Its Recommendation Report to Plan Improvements

An Energy Performance Certificate explains how energy efficient a building is and how it could be improved, and it does not travel alone: it is accompanied by a recommendations report which provides more detailed information about improvement measures¹. That report, rather than the coloured band on the front page, is the part worth reading before any money is spent. It sets out cost effective measures a householder or business can take to improve efficiency and the rating, from low energy bulbs to upgrading insulation, and the measures are modelled in the order given².

The certificate is a useful starting point and nothing more. Northern Ireland guidance describes looking at an EPC as a good starting point to help improve the energy efficiency of a property³, while the Scottish Government has been blunt that certificates are "intended as a basic, standardised assessment and not a substitute for detailed, technical, retrofit assessment and advice"⁴. Government research published in May 2026 compared modelled energy use with monitoring data to identify inaccuracies in certificates and to examine weaknesses in current assumptions and processes, including defaults and assessor practices⁵. The figures printed on a certificate are modelled, not metered.

Certificates are valid for a maximum of ten years, or until another is commissioned for the same building, whichever comes sooner⁶, and they are required when selling or letting an existing building. Both the certificate and the register entry behind it are changing: Scotland moves to a new-style certificate from 30 April 2028, and the calculation method used across the UK, the Standard Assessment Procedure, is to be replaced by the Home Energy Model.

What the certificate and its recommendations report actually contain

The certificate itself is a standardised summary of the building's modelled performance, and the required content includes a recommendation report¹¹. Regulations require that report to be included unless there is no reasonable potential for energy performance improvements¹², which is why a very small number of already-improved homes receive a certificate with little or nothing attached.

The recommendations report lists measures with indicative costs and indicative savings, and it is the document that connects a rating to a plan of work. Guidance for Northern Ireland describes it as a report setting out cost effective measures to improve energy efficiency and the rating, giving low energy bulbs and upgrading insulation as examples². Certificates are also the basis of many energy efficiency policies in the domestic built environment⁵, which means the same document is doing two different jobs: informing a household, and defining eligibility and standards for government.

Awareness of the improvement advice is thinner than the policy weight placed on it. In the Winter 2025 public attitudes tracker, 32% of those aware of certificates recalled seeing the section in their home's certificate that recommends ways to improve energy efficiency; among those who had seen it, two in three (65%) said they had made changes, small or large, based on the recommendations⁸. That is a reasonable conversion rate from a document most people meet once, at the point of buying or renting.

How the rating is worked out: SAP, standard occupancy and modelled costs

Assessors use the Standard Assessment Procedure to determine the energy efficiency rating of a home, with a reduced version, RdSAP, applied to existing homes where full information may not be available¹³. The content of the domestic certificate is produced by calculations carried out in that methodology¹⁴, and the procedure also underpins the approved products and calculation infrastructure used for certificate production¹⁵.

Two features of the method explain most of the gap between a certificate and a household's own experience. The first is standard occupancy: standard assumptions are made about occupancy and use, so that different buildings can be fairly compared¹. A comparison tool has to hold the occupants constant, so it cannot describe how a particular family heats a particular house. The second is standardised fuel prices. The supplementary cost information used on domestic certificates is updated quarterly¹⁴, so the cost figures a reader sees reflect a modelled tariff at a point in time rather than what the household pays.

The method is being replaced. The Standard Assessment Procedure is to be replaced with the Home Energy Model¹⁶, and the 2026 accuracy research was designed to support updates to the procedure and to inform its successor, along with the processes surrounding the generation and use of certificates⁵.

The metrics themselves are contested. The Climate Change Committee has described the ratings as an important policy tool, used to define standards and targets for reducing emissions from homes, but poorly suited to that role, and has recommended four primary metrics in real-world units¹⁷:

Source: Climate Change Committee advice on reform of domestic rating metrics¹⁷.

Reading the report: the measures are cumulative, in the order given

The list is not a menu of independent options. Each measure is modelled on the assumption that the ones above it have already been carried out, so the saving attached to a heating measure near the bottom of the list assumes the insulation above it is in place. Picking the fourth item and skipping the first three will not deliver the fourth item's printed saving. This is the single most common misreading of the document, and it is also why the order broadly matches a fabric first sequence rather than a shopping list.

Assessors have limited freedom over that list. They may suppress recommendations if there is evidence to justify doing so, but they cannot add additional recommendations¹⁸. A measure that is obviously right for a particular house, but which the software does not generate, will simply not appear. In Scotland, the wording on new-style certificates changes: the Scottish Government has decided to rename recommendations as "Potential Improvement Options"⁴, and where a polluting heating system is present, the certificate will set out potential improvement options to move to a non-polluting heating system on a technology-neutral basis⁴.

For a household, the practical reading order is: check which measures are marked as already installed, read the remaining list top to bottom as a sequence, and treat the costs as indicative starting points for quotes rather than budgets. The related pages on the order of energy improvements and where to start work through that sequencing in detail.

What the recommendations leave out

The list is generated, not designed. It does not consider the condition of the building, the moisture risk of a particular wall construction, the ventilation strategy, the state of the roof, or whether the household can live in the house while the work is done. Scottish Government policy work on retrofit assessment has been explicit that ratings do not always capture the true efficiency of a retrofit, and that measures such as PV panels or air source heat pumps may improve a score while failing to address fundamental building issues such as poor insulation or moisture risks¹⁹.

Government has also declined to make certificates carry that weight. In consulting on reform, the Scottish Government said it did not propose for certificates to be a substitute for a more detailed or specialist retrofit advice or technical survey, such as assessment following PAS 2030 or PAS 2035²⁰. A certificate is therefore a filter, not a design. The fuller documents are described on the pages covering whole house plans and retrofit assessors and coordinators.

Heat pumps are a frequent absence. Guidance notes that heat pumps are best suited to buildings with good insulation levels, and that insulation may need to be added internally or externally where homes do not already have good levels²¹. Where the modelling does not find the fabric sufficient, or where the measure sits below others in the sequence, no recommendation appears, and the household is left to take that question to a home energy assessment instead.

How far the cost and saving estimates can be trusted

The estimates are modelled outputs, and their accuracy has been formally investigated. The 2026 accuracy research compared modelled energy use and internal temperatures with monitored data from large-scale datasets, to provide empirical evidence on the accuracy of certificates and the Standard Assessment Procedure⁵. Its aims included identifying weaknesses in current assumptions and processes, including defaults and assessor practices, and developing insights to improve modelling algorithms and enable dynamic updates when building changes occur, so that future models better reflect real-world energy performance⁵.

Three things drive the gap between the printed saving and the delivered one. Standard occupancy means the assumed heating pattern, hours and internal temperature are not the household's own¹. Standardised fuel prices, refreshed quarterly¹⁴, mean that a saving stated in pounds is a modelled tariff calculation and moves when prices move. And default values fill the gaps where the assessor could not see or evidence a construction, which is the point at which two assessors can produce different certificates for the same house.

None of this makes the report worthless. It makes it a ranking rather than a forecast: reliable about which measures matter most in this particular building, weak about the exact pound figure attached to each. Households wanting a number they can hold to should baseline their own energy use first and measure results after the work.

Cost, validity and getting a new or corrected certificate

Only an accredited energy assessor can produce a certificate, and they will visit the property to carry out the assessment². Qualified assessors can be found on the EPC register²³, and the certification body that accredits an assessor is listed as "scheme details" beneath their contact details on the register²⁴, which is the route to a complaint or a correction.

Prices are not fixed. Trading standards guidance states that the cost will vary from one company to another and that householders will have to shop around for the best price, with size, location and age of building affecting it⁶. One consumer estimate cited by Climate Action Wales puts the usual range at £50 to £150⁷. Some local schemes help: SHINE London offers limited funding towards the cost of getting a new certificate as part of Warm Homes: Local Grant support²⁵.

Nothing invalidates a certificate because improvements have been made. A new assessment is the only way the register reflects new insulation, a new heating system or solar panels, which matters when selling, letting or applying for a scheme. Buyers and prospective tenants must be given the certificate at no cost, and a buyer receives a copy from the seller that can be reused within the period of validity².

Renting and selling: the rules that shape priorities

A certificate is required when selling or letting an existing building²³, and must be provided when a building is advertised for sale or for let to a new tenant³⁰. Where a building is advertised for sale, the rating must be included in the advertisement³¹. Under the 2008 regulations, the relevant person must make available free of charge a valid certificate to any prospective buyer or tenant at the earliest opportunity and before contract³², with the duty applying to rental of existing dwellings from 30 December 2008³². A narrow exemption applies where the building is to be demolished or subject to major renovation following the sale or rental, or where the buyer or tenant intends that³³. Government has said it intends to update regulations so that a certificate is required at the point of marketing rather than the point of sale or rent³⁴. Failure to provide the information can attract a penalty charge notice of £500 or more¹⁰, and not having a certificate at all can lead to enforcement action and a penalty charge notice².

For landlords, the minimum standard is the fixed point around which the recommendations report is read:

• England and Wales: no property without at least a band E rating can be let unless an exemption applies³⁵. Properties currently let at band F or G must be improved to a minimum of E, or an exemption registered where applicable³⁶, and the published exemptions guidance works to the same band E threshold³⁷.
• Proposed tightening: the Government's preferred option has been to require domestic rental properties to meet band C at a minimum for new tenancies from 1 April 2025 and for all tenancies by 1 April 2028³⁸. A 2025 consultation proposed allowing properties with a current band C certificate to be recognised as compliant under the future standard until the certificate expires³⁹.
• Scotland: an earlier consultation set out a minimum band E at the point of rental from 1 April 2019, with improvement within six months of a minimum standards assessment and all dwellings to reach that rating by 31 March 2022⁴⁰. Later policy documents commit to regulations requiring private rented sector properties to reach a standard equivalent to band C, where technically feasible and cost-effective, at change of tenancy.
• Grant eligibility: Warm Homes: Local Grant support covers privately rented properties with a rating of band D or E⁴¹.

Tenants who cannot commission work themselves will find the practical routes on the page covering where to start if you rent.

Scotland: a different certificate, register and timetable

Properties in Scotland are covered by a separate service, the Scottish EPC Register⁴², and the Find an Energy Certificate service for England, Wales and Northern Ireland points users there⁴³. A requirement to issue certificate data to a register is long established in the Scottish regulations⁴⁴.

Scotland is reforming the certificate itself. Regulations will introduce new ratings, redesigned certificates and improvements to the operational infrastructure³⁰. New-style certificates are introduced from 30 April 2028⁹, and between 30 April 2028 and 30 April 2029 a property can be sold or let using either the existing certificate and recommendations report from the 2008 regulations or a new-style certificate and property report from the 2025 regulations⁹. The redesigned certificate follows a first phase of user testing, with a second phase before the regulations come into force, and its introduction will coincide with the regulations bringing the new rating system into force⁴. The Scottish Government has said the new rating system could support proposed regulations such as a private rented sector minimum energy efficiency standard⁴⁵.

The register is also changing hands. The regulations appoint the Scottish Ministers as Keeper of the Register and bring it in-house to the Scottish Government, with the new register designed to be operational when the regulations require⁴⁶. Lodgement fees are proposed to fund the new register, a new calculation methodology (the Home Energy Model and an updated SBEM) and a new onsite audit and inspection function within the Scottish Government⁴⁷. Non-personal data, including the report reference number, will be shareable by the Keeper, with names and homeowner details excluded⁴.

Northern Ireland uses its own register, which issues energy performance certificates, display energy certificates for public buildings, and air conditioning inspection certificates and reports⁴⁸. For advice on certificates, or where one has not been made available to a buyer or new tenant, the route is the local district council building control².

Using the certificate as the first step towards energy independence

The certificate tells a household two things that bear directly on independence from imported energy: how much demand the fabric creates, and what the heating system is. Where a polluting heating system is present, a Scottish new-style certificate will set out options to move to a non-polluting system on a technology-neutral basis⁴, which is a statement about fuel dependence rather than about comfort. Reducing the space heating demand first is what makes a low-carbon heating system workable, since heat pumps are best suited to buildings with good insulation levels²¹.

The limits are equally plain. A certificate is a modelled comparison, produced under standard occupancy assumptions¹, using cost data refreshed quarterly¹⁴, by an assessor who cannot add recommendations the software has not generated¹⁸. It will not tell a household how much electricity it can generate, how a battery would behave, or whether a wall can safely take internal insulation. And the Scottish Government's own reform case is that current metrics and ratings are not appropriate to drive the improvements needed in fabric and the move to zero direct emissions heating⁴⁹, reform being taken forward under the Heat in Buildings Strategy as advised by the Climate Change Committee⁴⁹.

Used properly, the recommendations report does three jobs: it establishes what the assessor recorded as already installed, it ranks the remaining measures in a defensible order, and it produces a set of questions for a fuller assessment. The steps beyond that, a whole house plan, a check on what grant help is available, and a decision on whether to retrofit in stages, are covered across the getting started guide.