What Does an EPC Assessor Do During a Home Visit?

When you book an EPC (Energy Performance Certificate), a qualified energy assessor will visit your home to inspect key elements that affect its energy efficiency. Understanding what happens during this visit can help you prepare and ensure accurate results.

Purpose of the EPC Assessment

The main goal of an EPC assessment is to evaluate your property’s energy performance and assign it a rating from A (most efficient) to G (least efficient). This rating helps buyers, tenants, and landlords understand the energy use and potential running costs of a property.

What Does the EPC Assessor Check?

During a home visit, the EPC assessor conducts a non-invasive visual inspection. They’ll record data for a software system that calculates your property’s energy efficiency. Here’s what they’ll typically inspect:

  • Loft Insulation: Thickness and type of insulation in the roof space
  • Wall Construction: Cavity, solid, or timber-frame walls
  • Windows: Double/triple glazing and age of installation
  • Heating System: Type, controls, and efficiency of boilers or heat pumps
  • Hot Water System: Cylinder insulation and heating sources
  • Lighting: Use of energy-efficient bulbs (e.g. LED or CFL)
  • Building Materials: Age, construction method, and extensions

How Long Does an EPC Assessment Take?

Most EPC home surveys take between 30 to 60 minutes, depending on the size and complexity of the property. You don’t need to move furniture or make structural changes, but access to all rooms, the loft (if safe), and the boiler is essential.

Do You Need to Be Home?

Yes, someone over 18 must be present to allow access to all parts of the property. It’s helpful to provide documents or evidence (e.g. receipts for insulation upgrades or window certificates) to support the assessor’s report.

What Happens After the Visit?

After collecting all the necessary data, the assessor inputs it into approved EPC software. The system generates a certificate showing:

  • Current and potential EPC rating
  • Energy usage and CO₂ emissions
  • Estimated costs for heating, lighting, and hot water
  • Recommended improvements and their potential impact

The EPC is then lodged on the national register and made available for download. You’ll receive a copy within 24–48 hours.

Why an Accurate EPC Matters

  • Property Sales & Rentals: Required by law in the UK
  • Government Grants: Some energy upgrade schemes require a current EPC
  • Legal Compliance: Landlords must meet a minimum EPC rating (typically E or above)