Does Apex Heat produce official energy performance certificates?
Not directly. Apex Heat does not sell energy performance certificates to building owners; it provides software for producing them. A qualified certificate author uses Apex Heat App to calculate the E-number according to the Ministry of the Environment decree, submits the certificate to the ARA energy certificate register directly from the software, and sees at the same time which energy class the building reaches with each investment and which of them are worth recommending. The building owner receives the certificate from the author who uses the software.
9/17/2026
Who is Apex Heat App for when producing a certificate?
Energy performance certificate authors, engineering firms and energy consultants who produce certificates for their clients. The certificate is always signed by an author who holds the certificate author qualification. Apex Heat is the software supplier, not the author.
If you own a building and need a certificate, order it from a qualified author. Many firms using Apex Heat App produce certificates; you can also contact us and we will point you to one. Go to the contact form.
How is the certificate calculated in Apex Heat App?
The E-number is calculated with the tables of the Ministry of the Environment's energy certificate decree and the reference weather of the climate zone, not with the actual weather at the building's location. The building is divided into usage parts and zones, each zone's net energy need, system losses and purchased energy are calculated separately, and the results are combined weighted by floor area. Purchased energy weighted by the energy form factors, per heated square metre, is the E-number, from which the energy class is read.
Input data comes from the register, from the existing certificate and from the author's own observations. The existing certificate can be imported as a file, and the software reads the input data from it for the new certificate. For every field the software shows the estimate and what it is based on, and the author replaces the estimate with their observations.
How is the certificate submitted to the certificate register?
The finished certificate is converted to the file format of the ARA energy certificate register and submitted from the software. If the certificate lacks data the register requires, the submission stops with an error instead of sending an incomplete certificate. Any remarks the register returns are shown to the author.
How does the software show which investments improve the energy class?
The same certificate calculation runs for every measure scenario: heat pump, solar power, envelope energy efficiency measures and their combinations. Alongside the current E-number and energy class, the author sees which class each measure and combination reaches, together with the measure's investment, annual savings and net present value. The certificate's improvement recommendations are filled from these results.
The result is not always what one expects. In an apartment building in Helsinki built in 1951 the current class is F. The most profitable investment, an air-to-water heat pump, leaves the class at F, because in the E-number electricity is weighted with a higher energy form factor than district heating. Envelope energy efficiency measures raise the class to D, and the best combination of individual measures reaches C, but every envelope measure has a negative net present value. The author sees both sides at once and can recommend what the client is after: the best class, the best return or a balance of the two. Read why the calculation can be trusted.
What else does the software calculate beside the certificate?
- Renovation compliance according to the Ministry of the Environment decree 4/13 for a building being renovated, as an attachment to the permit application.
- Energy grant: a residential building's eligibility for the energy grant and the amount, based on the E-number improvement.
- Emissions and pathways: carbon dioxide emissions, CRREM decarbonisation pathways and an EU taxonomy assessment.
- Energy audit report in Word or PDF format, presenting the certificate scenarios with charts.
Can a certificate be produced with an AI assistant?
Apex Heat provides an MCP connector through which Claude, ChatGPT or another AI assistant can create a project, enter input data, read the E-number and the scenarios, and generate a report. The certificate is still checked and signed by a qualified author. The connector is currently available to selected customers. Read how to set up the connector.
How do I get started?
By getting in touch through the contact form. Apex Heat App can be tested free of charge, and the software runs in the browser. Go to the contact form.
Frequently asked questions about energy performance certificates
Apex Heat does not produce certificates for building owners; it provides the software with which a qualified author produces one. Contact us and we will point you to an author who uses the software.
Yes, when it is produced and signed by a qualified certificate author. The calculation follows the Ministry of the Environment decree, and the certificate is submitted to the ARA energy certificate register from the software.
Yes. The same calculation runs for every measure and their combinations, and the author sees each scenario's energy class, investment and profitability side by side.
Yes. The existing certificate is imported as a file, and the software reads the input data from it for the new certificate.
Not always. In the E-number electricity is weighted by an energy form factor, so a heat pump can leave the class unchanged even though it is the most profitable investment. The software shows both the class and the profitability, so the recommendation can follow the client's goal.
Read more
Why can the calculation be trusted?
What the calculation is based on, how measured consumption is used and what the calculation does not know.
How easy is Apex Heat App to use?
What data is needed, how estimates work and what the software produces.
