With the investment plan requiring a large share of private funding, Gašperšič believes that Slovenia could implement it strategy of improving the energy efficiency of buildings as part of a modified system of private contracting.

The minister highlighted that the plan was not so much an investment fund as it is a mechanism supporting private investment with EU money. "Slovenia must therefore examine which projects are suitable for funding with private capital."

He said that the energy overhaul of buildings, a key project for restarting the ailing construction sector and helping Slovenia improve energy efficiency, could rely on a modified contracting scheme in which private partners would invest in upgrades and then be repaid from the savings.

A private investor, such as a supplier of district heating, would invest in insulation of buildings and then recoup the investment from the amount which is saved as users would continue to pay the same amount as before until the full investment is repaid.

The state-run SID export and development bank could also be involved in such a scheme.

Gašperšič made the comments after a EU ministerial dedicated to management of the energy union, at which the ministers decided that national plans for implementation of energy and climate goals should be ready by 2019.

The minister said it was too early to speak about the details of the Slovenian plan, but added that Slovenia was preparing energy guidelines that will form the basis for the national plan.

Meanwhile, Slovenia said it was happy with agreement on plans for a new system of energy labelling envisaging that negotiations will be opened with the European Parliament on the matter.

"This is a compromise proposal that is deemed suitable by Slovenian industry," said Gašperšič, explaining that producers such as Gorenje have called for gradual introduction of a new labelling system.