Energy audit: who must have one, when and how much it costs

Updated: 5 November 2026Author: NetVoice s.r.o.Reading time: approx. 5 min

Who must have an energy audit

The obligation arises from Czech Act No. 406/2000 Coll. on Energy Management, specifically from its § 9. What matters is the average annual energy consumption over the last three consecutive calendar years, not the size of the company or its line of business.

• Above 10 TJ per year (2 778 MWh), you are obliged to arrange an energy audit of your entire energy system.
• Above 85 TJ per year (23 611 MWh), a company must implement and certify an energy management system in accordance with ISO 50001.
• Below 200 MWh per year, the Act expressly excludes the obligation (§ 9 para. 4).

All forms of energy count towards consumption: electricity, gas, heat and fuels. Also include linked businesses with a stake of at least 50 %. The most accurate figures come from measurements, not just from invoices. If you are unsure, use our obligation test.

Special rules apply to public bodies (municipalities, regions, contributory and state organisations, state and public universities, and the Czech National Bank). You will find details in the obligation test.

When and how often the audit is carried out

The audit must be completed within one year of the obligation arising, based on consumption data for the three preceding years (§ 9 para. 8 point b). It is then repeated once every four years (§ 9 para. 2).

An older audit carried out under the previous rules remains valid for no more than four years from the entry into force of Amendment No. 87/2025 Coll. We recommend keeping track of the deadlines from the moment your consumption approaches the 10 TJ threshold. Preparing data in good time makes the audit cheaper and faster.

Who carries out the audit and what it contains

The audit may be carried out by an energy specialist with authorisation under § 10 of the Act, or by an authorised person from another EU Member State (§ 9 para. 8 letter a). The output is a written report, which you must submit on request to the ministry or the State Energy Inspectorate (§ 9 para. 9).

A good audit is more than a formal document. It usually includes:

• a description of the energy system and its boundaries,
• an energy consumption balance broken down by significant uses (technology, lighting, heating, compressed air and others),
• an assessment of the current state and identification of losses,
• proposal of savings measures with technical and economic assessment,
• an action plan that can actually be implemented.

The detailed content and requirements are set out in the implementing regulation to the Act. The better your consumption data, the more accurate the balance tends to be and the less has to be estimated.

What to watch out for when choosing a contractor

Choose your audit contractor as a partner, not as a supplier of a rubber stamp. In practice, it pays to verify:

• authorisation: whether the auditor holds energy specialist authorisation under the Act (or equivalent authorisation from another EU Member State),
• experience with your sector: a production plant has different significant energy uses than an office building,
• approach to data: whether the audit is based on actual measurements and invoices, or mainly on estimates,
• form of the output: whether the report contains specific measures with benefits and payback periods, not just general recommendations,
• continuity: whether the data and conclusions can be used further, for example for ISO 50001 or ongoing monitoring.

What can replace an energy audit

An ISO 50001 certified system replaces an energy audit (§ 9 para. 5), provided the certificate covers the entire energy management system and was issued by an accredited body. For companies above 85 TJ, certification is mandatory and a separate audit is then no longer required.

However, ISO 50001 requires continuous data and performance indicators (EnPI). Consider whether it would pay to switch straight from repeated audits to a permanent system with metering. We describe the procedure in the article ISO 50001 step by step and on the page Implementing ISO 50001.

What penalty applies for non-compliance

Failure to comply with the obligations under § 9 is an offence. A business (a legal entity or a self-employed individual) may be fined up to 5 000 000 CZK (§ 12a para. 1 let. o) and para. 4 let. b)). The same upper limit applies to public bodies (§ 12a para. 3).

Compliance is monitored by the State Energy Inspectorate (§ 13a para. 1). Offences are heard at first instance by its regional inspectorate, and appeals are decided by the central inspectorate (§ 12b). The amount of 5 000 000 CZK is the upper limit; the specific amount is set by the inspectorate according to the circumstances of the case.

A fine typically results from situations where a company fails to arrange an audit by the deadline after exceeding the threshold, where the audit is not available on request, or where it is prepared by a person without the required authorisation.

How much an energy audit costs

A fixed price cannot be quoted seriously without knowing your operation. The price of an audit depends mainly on:

• scope: the number of buildings, sites and technologies, and the complexity of the energy management system,
• quality of available data: whether you have sub-metering and historical data, or whether additional measurements or estimates are needed,
• depth of evaluation: the number of energy uses analysed and the level of detail of the proposed measures,
• number of energy carriers: electricity, gas, heat, fuels, compressed air,
• whether the audit is linked to ISO 50001 or to existing monitoring.

The cheapest route to a good audit leads through data. Companies that already measure consumption continuously have the documents ready, and the audit is faster. We will prepare a non-binding offer after a short consultation: energy audit.

Common mistakes that make an audit more expensive or devalue it

• Incomplete documentation. Missing invoices, meter readings or switchboard diagrams prolong the work and increase the share of estimates.
• Poorly defined boundaries. The audit should cover the entire energy management system, not just one hall or one energy carrier.
• Overlooked energy. Electricity and gas are accompanied by heat, compressed air, fuels and other energy carriers.
• Ignoring production. Without production data, it is impossible to distinguish savings from a drop in output.
• A report without implementation. Savings arise only when a measure is carried out and verified, not by handing over a document.

How to proceed in practice

1. Calculate your consumption for the last three calendar years across all energy types and work from the average.
2. Compare it with the thresholds of 2 778 MWh and 23 611 MWh and decide between an audit and ISO 50001.
3. Prepare the data: invoices, meter readings, switchboard diagrams, production data. Continuous metering simplifies the whole process (energy consumption monitoring).
4. Choose an authorised provider and agree the scope and deadlines.
5. Implement and evaluate the measures. An audit that ends up in a drawer is just a cost.

Frequently asked questions