Guide
EPC vs energy audit: which one you need and what each costs
Updated
People ask for an energy audit when the law wants an EPC, and buy an EPC expecting audit-level advice. They are different products at different prices, here is the split.
Two different tools
- EPC (Energy Performance Certificate)
- A standardised A–G rating produced with government software. Legally required when you sell or let a building, valid 10 years. It is a compliance document with generic recommendations, not a tailored survey (gov.uk).
- Energy audit
- A tailored survey of how your building actually uses energy: metering, heating, lighting, fabric, habits, with costed measures and payback periods. Voluntary for most (mandatory only under ESOS for large undertakings), and priced by the work involved.
Costs compared
| Product | Typical cost |
|---|---|
| Domestic EPC | £60–£120 |
| Commercial EPC | £150–£500+ by size and complexity |
| Domestic retrofit / home energy assessment | £150–£400 |
| Commercial energy audit | £500–£2,500+ by floor area |
When you legally need an EPC
- Selling or letting a home or commercial building, the certificate must be available to buyers or tenants.
- EPCs are valid for 10 years; check the national register before paying for a new one.
- Rented homes in England and Wales must meet at least EPC band E under the minimum energy efficiency standard, subject to exemptions (gov.uk MEES guidance).
When an audit is worth paying for
- You are planning a retrofit and want measures ranked by real payback, not the EPC's generic list.
- A commercial building's bills look wrong and nobody can say which plant is burning the money.
- A funder, landlord or lender wants evidence behind an improvement plan.
- You are in ESOS, in which case the audit is not optional, see ESOS explained.
If you only need to sell or let, buy the EPC and keep the change. If you want the bills down, the audit is the product that pays for itself, get both quoted via the form and compare.