Energy saving tips

A heat pump is one of the most effective investments for reducing heating costs, but the right choice requires prior analysis. The most important factor is the energy efficiency of the house — a poorly insulated building will consume too much energy even with a modern heat pump. We recommend having an energy audit carried out by an accredited energy consultant before purchasing.

When choosing a type, take location and climate into account. Air-to-water systems are the most common and affordable, while ground-to-water systems achieve higher efficiency (COP 4–5) but require drilling or ground collectors. Heat pumps are most efficient in low-temperature heating systems, such as underfloor heating or low-temperature radiators.

Before deciding, check available Eko sklad subsidies — co-financing for heat pumps in residential buildings can reach up to 35% of eligible costs. With subsidy support, the investment typically pays back within 7–10 years.

Facade thermal insulation is among the most effective measures for reducing heat loss. Through poorly insulated walls, a typical older house loses 25–35% of all heat. By installing 15–20 cm of expanded polystyrene (EPS) or mineral wool on the exterior facade, you can reduce these losses by 60–70%.

The external thermal insulation process (ETICS system) involves preparing the substrate, gluing and mechanically fastening insulation boards, applying reinforcing mesh with adhesive, and finishing render. It is essential that the work is carried out by a certified contractor who ensures correct vapour barrier and hydrophobic protection. Poorly executed facade work can cause condensation and mould.

It makes sense to replace windows at the same time as the facade, so that the entire thermal envelope is addressed comprehensively. Eko sklad co-finances comprehensive energy renovation with favourable loans and grants — the total co-financing amount for comprehensive renovation can reach up to 50% of costs.

Windows are often the weakest link in a building's thermal envelope. Old single or double glazed windows have a thermal transmittance (Uw) of 3–5 W/m²K, while modern triple glazed windows achieve values below 0.9 W/m²K. Replacing windows in an average house results in a 10–15% reduction in total heating costs.

When choosing new windows, pay attention to the overall thermal transmittance of the window (Uw), not just the glass. Quality frames made of wood, PVC or aluminium with thermal break significantly contribute to the overall value. For Slovenia, we recommend triple glazed windows with a Uw value of ≤ 1.1 W/m²K, which meet the requirements of the PURES-2 regulation.

Do not forget proper installation — poorly fitted windows will not achieve their declared values even if they are of high quality. We recommend installation using the RAL system with appropriate sealing on both the interior and exterior sides. Window replacement costs are eligible for subsidies under Eko sklad programmes.

Photovoltaic (solar) panels have become affordable and technically reliable. An average Slovenian house with 20–30 m² of solar panels (5–7 kWp output) covers 60–80% of annual electricity consumption. Combined with a heat pump or electric vehicle charging, the economic viability of the investment improves further.

Before installation, check the orientation and slope of the roof, shading from neighbouring buildings, and the structural capacity of the roof construction. The optimal orientation is south with a slope of 30–35°, but south-east and south-west roofs also give good results. In the self-supply system, surplus electricity is fed into the grid and returned to you in case of shortfall at no extra cost (netting).

Costs of connecting to the distribution network and obtaining approval vary by distributor, and the process typically takes 2–4 months. An investment in solar panels at Slovenian irradiance levels typically pays back in 8–12 years, and panels have a 25-year warranty and a lifespan of over 30 years.

Slovenia offers an extensive system of grants and favourable loans for energy renovation of buildings. The main source is Eko sklad, which publishes annual public calls for individuals. Subsidies cover thermal insulation of facades and roofs, window replacement, installation of heat pumps, solar collectors and photovoltaic systems, and comprehensive renovation.

For individual measures, grants range from 20 to 50% of eligible costs, depending on the measure and the energy class of the building. Higher co-financing is aimed at older buildings and measures that achieve the greatest energy savings. In addition to Eko sklad, European funds are also available under cohesion policy programmes for comprehensive renovation of multi-apartment buildings.

The application process requires an energy performance certificate for the building, quotes from accredited contractors, and completed forms from the call documentation. We recommend submitting the application before work begins, as funds are approved in advance. Free advice on available subsidies is provided by the ENSVET network, which operates within Eko sklad at most administrative units across Slovenia.