Using an EPC and Its Recommendation Report to Plan Improvements

An Energy Performance Certificate (EPC) explains how energy efficient a building is and how it could be improved, and every certificate comes with a recommendations report giving more detailed information about improvement measures¹. If you have bought or rented a home in the last decade, the certificate already exists: a copy is lodged on a national register and can be accessed free through the EPC register's search facility². The recommendations it lists, things like low energy bulbs or upgraded insulation, are the cheapest widely available picture of what your home could gain from improvement work².

The certificate is worth using, but only with its limits understood. Only 32% of people aware of EPCs recalled seeing the recommendations section in their home's certificate, yet of those who did see it, two in three (65%) said they had made changes, small or large, based on what they read³. So the report does influence what households do. What it cannot do is substitute for a proper retrofit plan: the Scottish Government states plainly that EPCs are "intended as a basic, standardised assessment and not a substitute for detailed, technical, retrofit assessment and advice"⁴. This page explains what the report contains, how its numbers are produced, how far they can be trusted, and how to turn them into a plan.

What the certificate and its recommendations report contain

An EPC has two parts that matter to a householder. The first is the rating itself, the familiar A to G band with a score, which explains how energy efficient the building is. The second is the recommendations report, which the certificate must include unless there is no reasonable potential for energy performance improvements⁸. In England and Wales the required content of the certificate includes this recommendation report⁹, and in Northern Ireland each EPC likewise comes with a report setting out the cost effective measures homeowners or businesses can take to improve energy efficiency and the energy rating, such as low energy bulbs or upgrading insulation².

The report is not a survey of your home. It is generated from the same modelling run that produces the rating, using what the assessor could see and record during a short visit, plus a set of standard assumptions. That makes it consistent from one home to another, which is its purpose: certificates exist so buildings can be fairly compared, not so one household gets bespoke advice. EPCs are the basis of many energy efficiency policies in the domestic built environment¹⁰, which is why their content follows a fixed template.

For planning work, the practical value of the report is as a starting inventory. It tells you which measures the model thinks apply to your building, roughly what each might cost, and roughly what each might save. It does not tell you whether those measures are right for your home in its actual condition, and it does not cover everything a whole house plan would. Treat it as the first document in the file, not the last.

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

To determine the energy efficiency rating of a home, EPC assessors use the standard assessment procedure (SAP), with a reduced version, RdSAP, used for existing homes where full information about the construction may not be available¹¹. The National Calculation Method database records that SAP supports the production of EPCs¹². The content of the domestic EPC, including the recommendations, is produced by calculations carried out in the SAP methodology¹³.

Three features of that methodology shape everything on the certificate:

• Standard occupancy. Standard assumptions are made about occupancy and use, so that different buildings can be fairly compared¹. The model does not know how many people live in your home, how warm you keep it, or when you are out.
• Fixed fuel prices. The cost figures behind the rating and the savings estimates use standard price data, which is updated quarterly¹³. They are not your tariff, and they are not today's prices.
• Modelled, not measured. The rating is a calculation, not a meter reading. Two identical houses with different occupants get the same rating.

Change is coming. The Standard Assessment Procedure, the methodology used to calculate the energy efficiency rating of a home, will be replaced with the Home Energy Model in 2027⁶. The Climate Change Committee has also recommended that domestic EPCs should include four primary metrics, using real-world units and clear simple names: energy use intensity (kWh/m²/yr), space heating demand intensity (kWh/m²/yr), heating system type ranked in categories, and energy cost intensity (£/m²/yr)¹⁴. Those metrics would tell a householder far more about their actual building than a single letter band does.

For now, the practical implication is simple: the rating and the savings figures on your certificate describe a standardised model of your home, not your home as you live in it. A household that heats sparingly may see smaller savings than the report suggests; one that heats more may see larger.

Understanding the report: improvements build on each other in sequence

The recommendations report provides more detailed information about improvement measures¹, and the order in which they appear is not arbitrary. The list is generated so that measures build on one another: the savings shown for a later measure assume the earlier ones are already done. Reading the report as a menu to pick from, rather than a sequence, misstates the savings.

That matters because the single most common mistake in home energy work is installing the expensive technology before the cheap fabric measures that determine how well it performs. The report's ordering broadly reflects the order of energy improvements logic: stop heat escaping first, then improve the heating system. If the report lists loft insulation before a heating system upgrade, the saving quoted for the upgrade assumes the insulation is in place.

In Scotland, the terminology is changing: the Scottish Government has decided to rename "recommendations" on EPCs as "Potential Improvement Options"⁴. The substance is the same, a list of measures the model considers applicable, but the new name is a more honest description of what they are: options to consider, not instructions.

Two constraints on the list are worth knowing. EPC assessors may suppress recommendations if there is evidence to justify doing so, but they cannot add additional recommendations¹⁵. So a measure that would genuinely help your home can be absent simply because the standard list does not include it for your building type. And the savings figures attached to each measure are modelled under those standard assumptions described above, so they are indicative, not quotes.

What the suggested measures do not cover

The gaps are as important as the list itself. The Scottish Government's position, set out in its EPC reform response, is that EPCs are a basic, standardised assessment and not a substitute for detailed, technical retrofit assessment and advice⁴. The consultation that preceded it was explicit that EPCs are not proposed as a substitute for more detailed or specialist retrofit advice or technical survey, such as assessment following PAS 2030/2035¹⁶.

What that means in practice:

• Assessors cannot add measures. The recommendation list is fixed by the methodology; an assessor may remove an item with evidence but cannot insert one¹⁵.
• Building condition is not assessed. A review of retrofit assessment in Scotland found that EPC ratings do not always capture the true efficiency of a retrofit: measures like PV panels or air-source heat pumps may improve an EPC score while failing to address fundamental building issues such as poor insulation or moisture risks¹⁷.
• Your household is not in the model. Occupancy and use are standardised¹, so the report cannot tell you whether your bills will actually fall by the amount shown.
• Interaction between measures is simplified. The model treats measures in a fixed sequence, not as the interdependent system a real building is.

This is why the EPC sits at the bottom of the assessment hierarchy. A home energy assessment or a full retrofit assessment covers condition, moisture, ventilation and household behaviour that the EPC visit does not. The EPC tells you what the standard model thinks about your standardised house; the deeper assessment tells you what is actually true of your real one.

How reliable the cost and saving figures are

The honest answer is: treat them as rough indications, and know that the system's own designers agree. Government research published in 2026 compared modelled energy use with monitoring data to identify inaccuracies in EPCs and propose improvements, examining weaknesses in current EPC assumptions and processes, including defaults and assessor practices¹⁰. That research was commissioned precisely because the gap between modelled and real performance is a known problem, and it is intended to support the EPC reform and ensure future models better reflect real-world energy performance¹⁰.

The Climate Change Committee has been blunter still. Its advice on EPC reform states that the ratings on EPCs are an important policy tool, used to define standards and targets for reducing emissions from homes, but that they are poorly suited to that role¹⁸. The same point is made in the Committee's parallel advice to the UK Government¹⁴. When the body that advises both governments on emissions policy says the metric is poorly suited even to its official purpose, a householder should be cautious about using its savings figures as a spending plan.

Three specific weaknesses follow from the methodology:

1. Defaults stand in for facts. Where an assessor cannot see or verify something, such as the insulation inside a cavity wall, a default assumption is used¹⁰. If the default is wrong, the rating and every saving figure derived from it are wrong.
2. Costs are standardised and quarterly. The cost information behind the certificate is updated quarterly¹³, so it lags the market and takes no account of your home's access, size or condition.
3. Savings assume standard occupancy. A home occupied all day and one empty all week get the same modelled saving¹.

None of this makes the report useless. It makes it a screening tool: good for identifying which measures are worth investigating, poor for setting a budget. Before committing money, baseline your energy use from your own meters and bills, and check the payback periods for the measures the report flags.

Fees, certificate lifespan and arranging a replacement or revised one

An EPC is valid for a maximum of ten years, or until another EPC is commissioned for the same building, whichever is sooner⁵. Improvements you make do not update the certificate on the register: if you install solar panels or insulation and want the rating to reflect it, you need a new assessment. Research is under way to develop insights that would enable dynamic updates to EPCs when building changes occur¹⁰, but that is not how the system works today.

On cost: the price of an EPC varies from one company to another and depends on the size, location and age of the building, so you have to shop around for the best price⁵. There is no fixed national fee, and the figures quoted are installer or assessor prices, not regulated ones. In London, the SHINE referral service offers limited funding towards the cost of getting a new home energy certificate¹⁹.

An EPC can only be produced by an accredited energy assessor who will visit the property to carry out an assessment². Qualified assessors can be found on the EPC register²⁰. In Northern Ireland, your local district council building control is the contact for advice on EPCs, including if one has not been made available to you as a buyer or new tenant².

If the certificate contains a mistake, the route is back through the assessor and their accreditation scheme, who can correct or reissue it. Mistakes most often arise from those default assumptions¹⁰, so if you have evidence, for example a builder's invoice for cavity wall insulation, it is worth raising. Not having an EPC at all where one is required could lead to enforcement action and the issuing of a penalty charge notice².

Landlords and sellers: the regulations guiding their choices

An EPC is required when selling or letting an existing building²⁰, and EPCs must be provided when a building is advertised for sale or for let to a new tenant²¹. The underlying duty dates to the 2008 regulations: where a building is to be sold or rented out, the relevant person must make available free of charge a valid EPC to any prospective buyer or tenant at the earliest opportunity and before contract²². Buyers and prospective tenants are entitled to the EPC at no cost, and a buyer receives a copy from the seller that can be reused within the period of validity². The UK Government also intends to update regulations so an EPC is required at the point of marketing a property rather than the point of sale or rent²³.

There is a narrow exemption: the duty does not apply to a building to be sold or rented out where, following the sale or rental, the building is to be demolished or subject to a major renovation, or the prospective buyer or tenant intends to demolish or undertake a major renovation²⁴.

For landlords, the sharper question is the minimum standard. A Commons committee report on the private rented sector noted the government's preferred option to require landlords to ensure domestic rental properties meet EPC C at a minimum for new tenancies from 1 April 2025 and for all tenancies by 1 April 2028²⁵. In Scotland, the stated plan across successive heat buildings documents has been to require private rented sector properties to reach a minimum standard equivalent to EPC C, where technically feasible and cost effective, at change of tenancy²⁶. These are policy commitments and consultation positions rather than settled law as stated, so check the current position before relying on either date.

For an owner-occupier, none of these rules bind, but they still shape priorities in two ways. If you might let or sell within a decade, the certificate's rating has a legal and market life beyond your own use. And the direction of policy, towards fabric first and low-carbon heat, tells you which recommendations are likely to matter most over the life of the work you do. Our page on setting a target for your home covers how to choose between an EPC band, a bill reduction or low-carbon heat as the goal.

Scotland: its own certificate, register and schedule

Scotland is reforming its EPC system on its own schedule, and the changes are substantial. The Scottish Government's response to its EPC reform consultation confirmed plans to reform EPCs by introducing new ratings, redesigning the certificates, and improving the operational infrastructure²¹. The redesigned certificate is based on a first phase of user testing, with a second phase to follow before the regulations come into force, and its introduction will coincide with the regulations bringing the new rating system into force⁴.

The register itself is changing too. The Energy Performance of Buildings (Scotland) Regulations 2008 introduced a requirement to issue EPC data to a register²⁸. Under the 2025 regulations, the Scottish Ministers will be appointed as Keeper of the EPC Register, bringing the register in-house to the Scottish Government, with the new register designed to be operational when the regulations come into force²⁹. A technical consultation is planned on the level of EPC lodgement fees to support the new technical infrastructure³⁰. Non-personal register data, including the EPC report reference number, will be shareable by the Keeper, though names and homeowner details are not included⁴.

The timetable for households:

The Scottish Government's own rationale for the reform is direct: the metrics and ratings EPCs currently use are not appropriate to drive the improvements needed in the fabric of homes and the move to zero direct emissions heating systems³¹. Where a polluting heating system is present in a home, the reformed EPC will set out potential improvement options to move to a non-polluting heating system on a technology-neutral basis⁴, which is a significant change from the current fixed recommendation lists.

The certificate as a starting point for self sufficiency in energy

For a household working towards energy independence, the EPC is the free, already-existing first document in the file, and its best use is as a screening step before any money is spent. The sequence that follows from everything above is straightforward:

1. Find and read the certificate. Search the register, read the recommendations in the order given, and note which measures the model flags for your building².
2. Check the numbers against your own use. The model assumes standard occupancy and fixed prices¹; your meters and bills are the real baseline.
3. Investigate the fabric measures first. The report's ordering reflects the logic that fabric work determines everything downstream, and the Scottish review confirms that ratings can miss fundamental issues like poor insulation¹⁷.
4. Get a proper assessment before major work. The EPC is explicitly not a substitute for detailed retrofit assessment⁴; a whole house plan or PAS 2035 assessment covers what the EPC visit cannot.
5. Check grant help before budgeting. The certificate's cost figures are standardised and quarterly¹³; actual costs and available support, via finding grants before you start, determine what you actually pay.

Two limits on independence deserve stating plainly. First, the certificate itself changes under you: SAP is replaced by the Home Energy Model in 2027⁶, Scotland's new-style certificates arrive from 30 April 2028⁷, and the metric you plan against today may not be the metric that counts when you sell or let. Second, the EPC's cost figures are built on standard fuel prices¹³, and the Climate Change Committee has urged that electricity be made cheaper for consumers, since the relative price of electricity to gas shapes whether a heat pump saves money regardless of what any certificate models³². A household planning to move off gas should not treat the certificate's savings line as the last word on the economics.

One further caution for heat pump planning: the product eligibility list used for the Boiler Upgrade Scheme does not consider the SCOP (seasonal efficiency) of heat pumps³³, so grant eligibility and modelled performance are separate questions. The EPC can start the journey towards a self-sustaining home, but the plan that finishes it needs your own numbers, a proper assessment of the building, and a check of the rules that will apply when the work is done. Our planning for energy independence page picks up from here.