A home energy audit should help you decide what to change, why it matters and what evidence supports the recommendation. Start with your bills and a walk-through of the property. Pay for a professional assessment when you need a diagnosis or a plan for work that goes beyond those basic checks.
This checklist covers a practical first review, the difference between an EPC and a more detailed assessment, and the questions to ask before commissioning a survey. No fixed saving applies to every home. The useful result is a prioritised plan for your property and how you use it.
- Start with bills - Gather 12 months of consumption if available, and compare kWh alongside prices and meter readings.
- Follow the 4-step checklist - Review bills, inspect rooms safely, check existing controls and find the official advice route for your nation.
- Define the assessment - Agree the inspection, tests and written report before paying; an EPC does not diagnose every problem.
- Avoid promised savings - Ask for property-specific assumptions, costs and priorities before committing to insulation, heating or generation equipment.
What does a home energy audit include?
The term can mean anything from an online questionnaire to a detailed building assessment. Agree the scope before booking. A useful audit connects the building’s condition, heating arrangements and household energy use to specific recommendations, with costs and savings assumptions you can inspect rather than a guaranteed bill reduction.
For a first review, gather recent bills, meter readings, the heating-control instructions and any EPC or records of previous insulation work. Note which rooms feel cold, when condensation appears and whether the problem changes with the weather or heating schedule.
A specialist may offer measurements or investigations beyond this review, but do not assume that thermal imaging, airtightness testing or a full heating design is included. Ask which questions each test would answer, what conditions it needs and how it will affect the recommendations.
Is an EPC the same as an energy audit?
An EPC is a useful starting record of a home’s assessed energy performance and suggested improvements. It does not explain every household’s bills or diagnose every building problem. A separate assessment may be useful when you need to investigate a cold room, damp, unusual consumption or a planned renovation.
Government EPC guidance for England and Wales explains that the assessment uses standard occupancy assumptions. Its estimated running costs will not necessarily match your own usage. It also distinguishes an energy assessment from a safety or maintenance inspection.
| Option | Useful for | Check the limit |
|---|---|---|
| DIY bill and room review | Identifying questions, recording usage and spotting obvious control problems. | It is not a building survey or a diagnosis of damp or heating faults. |
| EPC | Reviewing assessed performance and recommendations for the property. | Check the assessment date and whether later improvements are reflected. |
| Professional assessment | Investigating a defined problem or planning coordinated improvements. | The inspection, testing and deliverables depend on the agreed scope. |
If you need a new EPC, GOV.UK’s assessor service provides the relevant routes, including a separate link for Scotland. Choose the assessment you actually need rather than assuming a report called an audit includes an EPC.
Step 1: understand what your bills show
Compare consumption in kWh as well as the amount paid. A bill can change because of a tariff change, an estimated reading or a different billing period. Gather enough information to separate those effects from a change in how much energy your home uses.
Use the checklist below to make a simple baseline. A full year is useful if you have it because heating use varies through the seasons. If you have just moved in, start recording now and label any comparison with the previous occupier as uncertain.
| Record | Why it helps |
|---|---|
| Billing dates and meter readings | Check that you are comparing equivalent periods and identify estimated readings. |
| Electricity and gas use in kWh | Separate consumption changes from price changes. |
| Unit rates and standing charges | See which costs depend on consumption and which do not. |
| Household changes | Record working from home, visitors, a new appliance or electric-vehicle charging. |
| Heating and hot-water schedule | Check whether settings still match when the home is occupied. |
If you have a smart-meter display or supplier usage history, look for patterns and write down questions. A spike tells you when something happened; it does not identify the cause by itself. Avoid changing several settings at once if you want to understand which change affected use.
Step 2: make a room-by-room checklist
Walk through the home and record what you can observe safely. Concentrate on evidence: draughts, visible gaps, damaged seals, condensation, heating controls and lights left on. Photograph problems for an assessor. Do not disturb wiring, remove appliance covers or enter a loft that you cannot access safely.
| Area | Record or check |
|---|---|
| Windows and external doors | Damaged seals, visible gaps, difficult closing and where draughts occur. |
| Walls, ceilings and floors | Where cold surfaces, staining or damp appear and when the problem is worst. |
| Loft | Existing paperwork or safe observations of insulation. Ask for inspection if access or condition is uncertain. |
| Heating | Schedule, thermostat location, room controls and rooms that fail to reach a comfortable temperature. |
| Hot water | When hot water is needed, the programmed schedule and any obvious leaks requiring repair. |
| Lighting and appliances | Bulb types, equipment left running and settings that no longer match your routine. |
| Ventilation | Extractor operation and any blocked or covered vents to raise with a suitable professional. |
Do not treat every opening as wasted heat. Energy Saving Trust’s draught-proofing guidance distinguishes unwanted draughts from necessary ventilation. Keep intentional vents, air bricks and extractor routes clear, including ventilation needed by combustion appliances. Get advice before sealing an opening if you do not know its purpose.
Record damp separately from the energy-saving list. A cold or stained patch is an observation, not proof that insulation is the correct repair. Ask for the cause to be assessed before covering it or commissioning work based on a photograph alone.
Step 3: check controls before buying equipment
Review the instructions for the controls you already own. Check the clock, programmed periods and room settings against your current routine. A confusing controller can make existing equipment hard to use. Ask the installer or manufacturer for help before assuming replacement hardware is the answer.
Write down your original settings so you can restore them. Make changes you understand and record the result. Do not alter boiler service settings, protective functions or hot-water hygiene settings as a DIY energy-saving experiment.
Keep maintenance and upgrades separate. If a boiler needs a service or has a fault, our guide to boiler servicing costs is a starting point for the maintenance question. An energy audit does not replace a service or a safety check.
For lighting, list the bulbs used most often and compare suitable replacements using actual wattage and hours. Our energy-efficient home lighting guide includes a worked calculation. Avoid applying its example saving to lamps with different power ratings or usage.
Step 4: get the right advice for your location
Use the official advice route for your nation before paying for a broad assessment. Online recommendations can help organise your options, but they rely on the information supplied. Treat them as a starting point for questions and quotes, especially where condition, moisture or construction type needs an inspection.
| Location | Starting point |
|---|---|
| England and Wales | GOV.UK’s home energy improvements service provides recommendations using property information. |
| Scotland | Home Energy Scotland’s Home Energy Check produces a personalised report. |
| Northern Ireland | Follow the Northern Ireland advice link on the GOV.UK energy-efficiency page. |
Home Energy Scotland says its online report is a first indication and recommends professional advice before committing to improvements. Check the report’s assumptions against your own fuel use. If an input is a default rather than something you supplied, mark it before comparing the suggested savings.
What should you ask a professional assessor?
Describe the problem you want solved and request a written scope. Ask about experience with your type of home, what access is needed, which tests are included and whether the assessor earns money from recommended installation work. A clear report should explain the evidence behind each recommendation.
| Question | What to look for |
|---|---|
| What will you inspect? | A named scope covering the issues you raised, with exclusions stated. |
| Do I need specialist tests? | An explanation of what a test would establish and why it is appropriate. |
| How are savings calculated? | Energy-use, tariff, occupancy and installation assumptions you can check. |
| What will I receive? | A written report with priorities, dependencies, estimated costs and uncertainties. |
| What experience do you have? | Relevant qualifications and work on homes with similar construction and problems. |
| Are you independent of installers? | Disclosure of referral fees, sales interests or installation services. |
| What does the quote include? | Total cost, taxes where applicable, travel, testing, report and follow-up questions. |
There is no single price that covers an EPC, a short home visit and a detailed diagnostic survey. GOV.UK says EPC assessment costs vary by assessor and property size. For a broader audit, compare quotes for the same written scope rather than treating the cheapest headline as an equivalent service.
Turn the findings into a practical plan
Give each proposed change a reason, an owner and a next step. Start with problems that need repair or diagnosis, then assess controls, smaller measures and larger projects. Ask whether one job affects another before signing contracts. The report should help sequence work, not become an unpriced shopping list.
| Priority | Example next step |
|---|---|
| Investigate or repair | Arrange assessment of a damp patch or a heating fault before choosing an upgrade. |
| Use existing equipment better | Correct a heating schedule, explain controls to the household and record the change. |
| Price a suitable improvement | Request comparable quotes with materials, ventilation implications and guarantees stated. |
| Plan a larger project | Check design, dependencies and permissions with appropriate professionals. |
| Measure afterwards | Keep installation records and compare consumption with notes on weather, occupancy and comfort. |
Do not add every predicted saving together without checking how the measures interact. Ask the assessor for a combined estimate and the assumptions behind it. A more comfortable home may also change how much heating you choose to use, so record comfort alongside consumption.
If solar generation is one of the recommendations, our guide to choosing solar panels can help with product questions. Keep that purchase tied to a property-specific assessment rather than using it as the default answer to a high bill.