Energy standards in new Czech flats and what they mean for bills

Two new flats of the same size, in the same district, sold by two developers. Both carry a class B energy certificate. One tenant reports bills that make a monthly budget easy, the other is surprised at the heating statement. The letter on the certificate was the same. What differed was everything the letter does not measure.

This explainer covers what the energy standards for new Czech flats actually require, what the certificate tells a buyer, and where the running costs come from. It quotes no tariffs or bills, because prices of energy move and a figure would be misleading within months.

What the standard requires

New buildings in Czechia must meet requirements on energy performance set by the Act on Energy Management and its implementing decree, which put into national law the EU rules on the energy performance of buildings. For new buildings the standard is the nearly-zero-energy building (budova s téměř nulovou spotřebou energie). It was phased in by building size from 2016 and has applied to all new buildings since 1 January 2020 (as of 2026; check the Ministry of Industry and Trade). In practice this pushes new flats into the better classes on the certificate, with good insulation, efficient windows, mechanical ventilation with heat recovery in many projects, and a low-energy heating source.

The next step is already agreed at EU level. The recast Directive (EU) 2024/1275 on the energy performance of buildings requires new buildings owned by public bodies to be zero-emission buildings from 1 January 2028, and all new buildings from 1 January 2030, with limited exemptions member states may allow. Until then the nearly-zero-energy standard stays the floor. The transposition deadline was 29 May 2026, and the Czech amendment and its detail are for the Ministry of Industry and Trade to confirm (as of 2026; check the ministry). For a buyer today the point is simple: a new flat is built to a higher standard than most of the existing stock, and that gap is likely to widen.

What the certificate tells you

The certificate (průkaz energetické náročnosti budovy, PENB) is a calculation. An energy assessor models the building: the insulation, the windows, the heating and hot-water system, the ventilation and the lighting where relevant. The model then assumes a standard pattern of use, a standard climate and standard internal temperatures. The result is a figure for the energy a building needs per square metre, and that figure is then placed in a class from A to G.

The seller or developer must show the certificate and hand it over, and the class is stated in adverts (as of 2026; check the Ministry of Industry and Trade). For a flat in a block, the energy bills for the last three years can stand in for the certificate in a resale, but the advert rules for that case have their own wording, so check the ministry's guidance. For the full rules, see our explainers on energy performance certificates and energy classes A to G decoded.

So what is the letter good for? It is a reasonable guide to the quality of the building envelope. A building in class A or B loses less heat than a building in class E, and that is a real advantage in a cold winter. It is not a forecast of your bill, because the model does not know how many people live in the flat, how warm they keep it, or what the energy costs.

The three things the letter leaves out

The energy source and its price. A building heated by district heating, one with a heat pump, one with a gas boiler and one with electric panels can all land in the same class. Their running costs will differ, because the price of heat, gas and electricity differs and moves. Our guides to heating systems and district heating describe how each one works and who sets the price.

How costs are shared. In a block, the heating and hot water are usually metered per flat or apportioned by a formula in the building's rules, and a share is charged by area regardless of use. Ask how the apportionment works, whether each radiator or flat has a meter, and what the annual settlement showed in comparable flats. The building's owners' association or the cooperative sets these rules, as described in service charges and building funds.

Your flat's position. A top-floor flat with a large glazed façade to the south, a corner flat with two exterior walls and a ground-floor flat above an unheated garage lose and gain heat differently. The certificate often rates the building, not your unit.

Comfort, not only cost

A well-insulated building with tight windows holds heat in winter, and in summer it can hold it too. Large glazing and no external shading make some new flats hot in July. Ask the developer how the flat handles solar gain: external blinds, cross-ventilation, or cooling. Mechanical ventilation with heat recovery saves heat, but it needs filter changes and some maintenance, and it is sometimes noisy. Visit the show flat in more than one season if you can, and ask residents of a finished building of the same developer how it behaves.

Ask the developer for these

A buyer in a new building can ask for documents that a resale buyer rarely sees. The developer should have the energy certificate for the building or an assessor's calculation for the project, a description of the heating and hot-water system, and the specification of windows and insulation. In the contract, look for the energy class promised and what happens if the finished building falls short. Our guide to buying a new-build flat from a developer lists the documents, and the handover checklist shows what to test when you take the keys.

Where to browse and what else costs money

New projects across the country can be browsed on the Novostavby.com directory of new-build homes (in Czech), and a map of developments (in Czech) helps you place one relative to transport. Energy is only one running cost. The others are the service charges, the contribution to the repair fund and, for owners, the annual property tax. Our article on hidden costs of a new-build flat covers what is not in the price list.

Frequently asked questions

Frequently asked questions

Does class A mean the lowest bills?

It means the lowest calculated energy need under standard use. Bills also depend on the heating source, the energy price, metering and how you use the flat.

Must a new flat have an energy certificate?

The certificate must be shown and handed over, and the class is stated in adverts. For a flat in a block, the building's certificate may be used or, in a resale, three years of bills can replace it (as of 2026; check the Ministry of Industry and Trade).

Are new flats cheaper to run than older ones?

Usually the envelope is better, so the heat loss is lower. Compare actual bills from similar buildings, because the heating source and the metering matter a great deal.

Will the standard get stricter?

Yes. Under Directive (EU) 2024/1275, new public buildings must be zero-emission from 2028 and all new buildings from 2030. Check the Ministry of Industry and Trade for the Czech implementing rules.

A practical next step

Ask the developer for the certificate, the heating description and a sample service statement from a finished building. Put the three beside each other. If any of them is missing, that is your answer on how well the running costs have been thought through.

This is a general explainer, not legal, tax or mortgage advice.