Energy Certification of Apartment Buildings: Obligations and Impact on Unit Pricing
Published 26 October 2026
When selling a building or residential unit, the seller must generally provide the buyer with an Energy Performance Certificate under the Czech law on energy management No. 406/2000 Sb. A lower energy class doesn't prevent the sale itself, but buyers factor it into their decision and the price they're willing to pay. It makes sense to know the certificate's grade before you put your building on the market.
Summary
- An Energy Performance Certificate is required when selling buildings and units; always verify the current scope of this obligation and exemptions in the Czech law No. 406/2000 Sb.
- The energy class won't prevent a sale, but it influences buyers' willingness to purchase, their operating cost expectations, and price negotiations.
- Investments in insulation and technical upgrades should be evaluated based on the return for your specific building, not by general rules.
- It's best to obtain the Energy Certificate as part of your preparation for dividing the building into separate units, before setting your sales prices.
What is an Energy Performance Certificate and when is it required?
An Energy Performance Certificate is formally called the Energy Performance Certificate (EPC). It is governed by the Czech law on energy management No. 406/2000 Sb. and its implementing regulations. The certificate is prepared by a qualified energy specialist and assigns the building to an energy efficiency class, ranging from best to worst, expressed in letters.
The law states that when selling a building or a unit, the owner must provide or make the certificate available to the buyer. The law also specifies when a certificate is required for new buildings, major renovations, or rental arrangements, and lists exemptions for certain building types. These requirements change over time, so always verify the current legal position before taking action, or consult an energy specialist.
For the owner of an apartment building, the practical conclusion is this: if you plan to sell units separately, the Energy Certificate is part of your sales documentation, just like an extract from the Czech Land Registry (katastr nemovitostí).
One Certificate for the entire building, or separate certificates for each flat?
For an apartment building, you need to decide whether to obtain a certificate for the building as a whole or for each flat separately. In certain cases, the law allows you to use a single certificate for the whole building if all flats share the same heating system and have similar construction. The conditions must be assessed based on your building's actual condition.
In practice, this means:
- a single certificate for the entire building is usually more cost-effective if your building is technically uniform,
- a separate certificate for each flat makes sense if units have different heating systems or have undergone individual renovations,
- the certificate must reflect the building's actual condition at the time of sale, not its condition before renovation.
Since flat buyers rely on standardised data, it's best to obtain the certificate after completing any upgrades, so it reflects the better final energy class.
How the energy class affects price and sale speed
It's impossible to give a general figure for how much the price of a flat will fall in a lower energy class; it depends on location, the condition of the building, and market demand. However, we can describe the mechanisms by which the energy class affects the sale:
- Operating costs. Buyers, especially those financing with a mortgage, factor in monthly heating and energy costs. A lower energy class means higher expected costs.
- Negotiations. A weak energy class becomes a reason for a price reduction, because the buyer includes the cost of future insulation or heating system replacement in their calculation.
- Time to sale. Flats in buildings with obvious energy deficiencies may sell more slowly, particularly if there are comparable properties on the market in better condition.
- Financing. Some lenders consider energy performance when assessing a loan; you must check the specific terms with your bank.
The energy class is therefore one factor among many, not the only one. Location, layout, and unit price often matter more. That's why it's wise to factor it into your calculations when planning your sale strategy.
Which upgrades improve the energy class and when they're worth the investment
An apartment building's energy performance improves mainly through these measures:
- insulation of external walls, roof, or ceiling above the top floor and below the basement,
- replacement of windows and external doors, or repairs to their sealing,
- modernisation of the heating system and pipework, hydraulic balancing and controls,
- improvements to hot water supply and, where possible, use of renewable energy sources,
- insulation and glazing of communal areas.
Whether the investment is worthwhile depends on the relationship between three factors: the cost of the measures, the improvement achieved in energy class, and the expected impact on unit sales prices. There is no simple rule. Measures that also address the building's technical shortcomings (leaks, dampness, worn windows) generally have a better return on investment than purely cosmetic upgrades.
You should also factor in any available grant schemes. Their terms change, so verify them with the provider before starting work, because some schemes exclude work that has already begun before the application is submitted.
Connection with building works and the building's legal status
Facade insulation or technological changes may, depending on their scope, require permission or notification under the Czech Building Act No. 283/2021 Sb. You must therefore include any required permissions in your schedule. At the same time, any such works must not conflict with your plan to divide the building into units: the declaration of ownership and definition of individual units under the Czech Civil Code No. 89/2012 Sb. is based on the building's condition, and if building works affect common areas, they must be reflected in the documentation.
Buyers become owners only when the property is registered in the Czech Land Registry (katastr nemovitostí) under the Land Register Act No. 256/2013 Sb. Therefore, provide the Energy Certificate when signing the contract, so that the energy performance information is clearly documented before the transfer.
How to incorporate energy certification into your sale preparation
When converting an apartment building for sale as individual units, the difference in value between selling the whole building and selling unit by unit is typically in the range of +20–40 per cent. The exact figure depends on a feasibility study, and your building's energy profile is one of the key inputs. Improvement in the energy class translates into higher unit prices, but it also increases your investment costs, so you need to compare both on the basis of actual figures for your building.
The recommended approach is:
- assess your building's current technical condition and estimated energy class,
- propose upgrade options and their likely impact on the class,
- compare the upgrade costs with expected unit selling prices,
- decide whether to carry out energy improvements before the sale, or to leave them to the buyers and reflect the cost in your price.
This step is part of the Audit and Plan, which is delivered within six weeks. Your project then passes through three gates (legal, permit, and sales gate), and only confirmed figures allow you to proceed to the next phase; the process is described on the How it Works page. Further questions can be found in the FAQ section.