An Energy Performance Certificate (EPC) is a key document for UK properties, used to show how energy efficient a building is and what improvements could reduce energy costs and carbon emissions. Whether you’re a landlord preparing for a new tenancy, a homeowner selling a property, or an estate agent coordinating compliance, getting the EPC right starts with supplying the correct information. The EPC assessment is based on physical property details, construction characteristics, and energy-related features that can sometimes be documented in advance. Knowing what information is required can help you avoid delays, rescheduling, or the need for repeat surveys.
At PropCert.co.uk, we support landlords, homeowners, and commercial stakeholders across the UK with EPCs and wider property compliance inspections. Because EPCs require specific inputs, collecting the right details before the assessment can make the process smoother and more accurate. Below is a practical guide to what information is typically required for an EPC, what you may be able to provide beforehand, and what may need to be confirmed on-site. If you’re preparing for an appointment, this checklist will help you understand what to gather and why it matters.
Core property information needed for an EPC
Most EPCs require baseline property data so the assessor can model the building correctly under the UK’s energy assessment methodology. You’ll generally need information that identifies the property and describes its type and basic layout. This includes the property address and whether it’s a house, flat, maisonette, or another building type. The assessor also needs details on the property’s size and how it’s arranged, because internal areas and characteristics influence heat loss and energy use.
- Property address and unit reference (especially for flats or units within a block)
- Property type (e.g., detached, semi-detached, terrace, flat)
- Floor area and number of floors/levels
- Construction period or approximate build date (if known)
- Any relevant extensions or conversions and when they were completed
- Heating and hot water setup type (e.g., boiler, communal system, heat pump—if applicable)
Where details are unknown, the assessor may estimate certain elements using visible indicators and standard assumptions. However, providing accurate information up front often improves the final EPC accuracy and reduces the likelihood of discrepancies later. If you have plans, refurbishment records, or previous EPC reports, these can also be helpful. For landlords managing multiple units, keeping a simple “property compliance file” can save time for each EPC renewal.
Heating, hot water, and insulation details you should gather
The biggest drivers of an EPC are the property’s heating system, insulation, and how the building is ventilated. As a result, the EPC assessor will request information about installed heating equipment and the insulation measures present. If your property has had upgrades—such as a newer boiler, additional loft insulation, cavity wall insulation, or improved windows—those details can directly affect the EPC rating. Having installation dates, model numbers, and specification sheets can be useful, especially when equipment identification is required.
- Boiler type and fuel (gas, oil, LPG, electric, communal, etc.)
- Boiler efficiency rating if available (or data from installation documentation)
- Heating controls (e.g., thermostats, timer controls, thermostatic radiator valves)
- Hot water system type and whether it’s combi, system boiler, or cylinder storage
- Loft/roof insulation (thickness, type, and whether fully insulated)
- Cavity wall insulation (filled, partially filled, or not present)
- Solid wall insulation (if installed) and its extent
- Floor insulation for suspended floors or other applicable areas
- Window glazing and frame type (single/double glazing, u-values if known)
- Draught proofing or other sealing measures (where applicable)
Even if you can’t provide every specification, you can still prepare by locating key documents such as boiler installation certificates, maintenance records, and insulation upgrade receipts. If you’re a landlord, tenant access and cooperation can also matter, because certain checks may require access to heating controls, loft hatches, or meter cupboards. The assessor may also need to verify visible features that cannot be fully confirmed from paperwork alone. Accurate information at this stage helps ensure the EPC reflects the property as it truly performs.
Ventilation, lighting, and evidence of energy-related improvements
Beyond insulation and heating, EPCs take into account how air flows through the property and the energy use of certain systems. Ventilation characteristics can influence calculations because they affect heat loss and indoor air conditions. In addition, EPCs consider lighting efficiency in many scenarios, particularly where lighting is relevant to the energy assessment model. If the property has had measures installed for energy efficiency—like smart heating controls or improved ventilation—having details can support accurate reporting.
- Ventilation method (natural ventilation, mechanical extract, trickle vents, etc.)
- Presence of extractor fans and where they discharge to
- Any passive ventilation features and whether vents are open and installed correctly
- Lighting details (e.g., type of lamps used where relevant)
- Renewable or low-carbon technologies (e.g., solar thermal, solar PV, heat pumps—if installed)
- Energy efficiency improvements evidence (invoices, certificates, and product specs)
If you’re preparing a new-build property, you may also be dealing with additional compliance evidence and assessment requirements. While standard EPCs focus on the property’s current energy performance, new-build EPC processes may require information connected to building fabric and services design. For developers and new-build providers, it can be especially important to ensure documentation is aligned to the required calculation method. PropCert.co.uk also supports new-build compliance needs such as SAP EPCs, along with related testing and reporting.
Practical EPC checklist before your appointment
If you want to reduce delays and help your EPC assessment run smoothly, use a focused “ready-to-assess” checklist. The goal is to ensure the assessor can confirm key elements of the property without unnecessary follow-ups. Tenants and homeowners often find it easier when a short list of tasks is completed ahead of time. This can also be important for landlords who manage multiple assets and need consistent turnaround times.
- Confirm who will provide access for interior checks and meter/controls locations.
- Locate boiler and heating documents (model, type, efficiency details, and any service records).
- Gather insulation evidence (loft details, cavity wall records, and any installation certificates).
- Make windows/frames easy to inspect (and note any upgrades you know about).
- Prepare any renewal or improvement details since the last EPC (if applicable).
- For flats, confirm the correct unit details and any communal heating/hot water information.
- If you have one, provide the previous EPC so changes can be identified quickly.
Once the assessor completes the survey, the EPC outputs rely on the gathered and verified information. That’s why accurate property details and access arrangements directly influence the final certificate. If you’re unsure what documentation you have or what matters most for your property type, PropCert.co.uk can help guide you on next steps. Our team supports landlords, homeowners, estate agents, and commercial property owners across the UK with compliant EPCs and wider property certification services.
If you need an EPC—or you’re also managing related compliance such as EICRs, Gas Safety Certificates (CP12), PAT testing, fire risk assessments, or asbestos surveys—contact PropCert.co.uk for expert support across your property portfolio.