Energy Certificate: A Key Construction Requirement

The Role of the Energy Certificate in Modern Building

1. What is an Energy Performance Certificate?

It is an official document that provides information about a building’s energy efficiency and includes recommendations for improvement. It is mandatory when selling or renting buildings or apartments for more than one year. It can only be issued by an independent licensed expert and is formally provided by authorized legal entities designated by the ministry. The certificate is valid for 10 years unless major changes affecting the energy performance of the building occur.

It is not just used to assess the current state but also serves as a tool for long-term property management. It includes clear energy indicators and recommended measures that can significantly reduce costs and environmental impact. It should serve as a reference point when deciding on renovations or investing in energy upgrades.

The energy certificate is also becoming a central element of both European and national efforts toward green transition. Buildings are among the largest energy consumers, and energy renovation is crucial for meeting greenhouse gas reduction targets. The certificate is therefore more than just a formality—it is a practical instrument for achieving measurable outcomes.

2. Types of Energy Certificates

There are two types:

– Calculated Energy Certificate (rEI) – based on estimated energy use, applied to new or old residential buildings.

– Measured Energy Certificate (mEI) – based on actual energy use, used for existing non-residential buildings.

3. Legal Obligation and Oversight

The energy certificate is regulated by the Energy Act (EZ-1). Its issuance, contents, methodology, and oversight are governed by specific regulations and technical guidelines, including PURES and TSG-1-004. Compliance is monitored by the competent ministry, and pricing is set by regulation.

Why Is the Energy Certificate Important?

1. Cost Reduction

One of the key advantages is a clear overview of a building’s energy consumption. It gives owners insight into current efficiencies and recommends measures that can reduce heating, cooling, and electricity expenses over time.

2. Increased Property Value

Buildings with higher energy ratings have better market value. Buyers and tenants can make more informed decisions based on the data provided. This is a crucial consideration in both investment and sales processes.

3. Contribution to Sustainable Building

Beyond financial benefits, it plays a broader role. It enables systematic national-level monitoring of building energy use, contributing to more sustainable urban development.

It’s also an important communication tool for investors. It helps explain a building’s quality and efficiency to the general public, banks, and insurers. Additionally, it’s required for applying to Eko Fund subsidies—often a decisive factor for renovation decisions.

When Do You Need It?

1. Property Sale or Rental

Sellers or landlords must provide a valid energy certificate before signing any agreement. This also applies to parts of a building (e.g., individual apartments). Without this document, a contract cannot be legally concluded.

2. Public Sector

Publicly owned buildings with more than 250 m² of usable floor space must display the energy certificate in a visible location. This is a transparency measure and sets an example for responsible spatial management.

Technical Aspects and Design Integration

1. Inclusion in the Design Phase

The energy certificate is more than just a legal requirement. Its true value comes when incorporated early in the design process. Using BIM technology enables dynamic energy simulations during the conceptual design phase, improving accuracy and reducing the need for later corrections.

2. Energy-Efficient Solutions

By applying modern architectural methods, quality insulation, double or triple glazing, and efficient heating/cooling systems, a building can achieve a higher energy class, which is reflected in the certificate.

More on Energy Classes, the Process, and Penalties

The certificate ranks buildings from energy class A1 (most efficient) to G (least efficient). The rating considers energy use for heating, cooling, hot water, lighting, and ventilation. A1 class buildings use less than 10 kWh/m² per year, while G class buildings exceed 250 kWh/m².

The issuance process includes a building inspection, project documentation review, and an energy calculation. For a single-family home, the cost typically ranges from €300 to €400. Legally, the certificate must be available to prospective tenants or buyers during the viewing stage, not only when signing a contract. Failing to comply may result in a fine between €250 and €2,500 for the owner.

The Slovenian Consumers’ Association (ZPS) recommends using the energy certificate as a diagnostic tool, even if not legally required—especially for older buildings, where simple measures can quickly improve energy performance. Combining energy renovation with aesthetic or functional interior updates is also encouraged.

How We Help at OD-DO

At OD-DO, we see the energy certificate not just as a document, but as a tool for sustainable building. Our approach is based on integrated design that considers functionality, aesthetics, and energy efficiency.

Our services include:

– Concept design with 3D visualizations

– Floorplan reorganization and interior planning

– Preparation of implementation plans with energy efficiency in mind

– Supervision of execution and coordination with contractors

– Collaboration with independent experts to obtain the energy certificate

By using BIM tools and prioritizing sustainable design, we contribute to optimal energy solutions from the early stages of planning. Every project is treated individually, taking into account the client’s preferences and spatial constraints.

Our goal is to create spaces that are not only visually refined but also effective in the long run and environmentally responsible.

Conclusion

The energy certificate is essential for every modern construction or renovation project—not just because of legal requirements, but due to the many benefits it offers to users and the environment. Integrating it in the early planning phase leads to better decisions, higher property value, and lower future costs.

At OD-DO architecture studio, we focus on integrated, energy-conscious architectural solutions. We make sure your project is designed with efficiency and compliance in mind—including a properly prepared energy certificate.

For more information about energy certificate, contact us using the form below.