On the Croatian real estate market, very popular are old stone houses that can be sold for a quite high price after their adaptation. However, the biggest issue for potential buyers and owners is the energy class of stone houses. These houses made of stone are usually in the center of an old town or a village, and they are perfect choice for all buyers who like traditional constructions. They were built in old times, very often more than a hundred years ago. If they are well renovated, they surely can serve to the generations to come. Thickness of old stone houses is usually between 60 and 70 centimeters. This kind of isolation efficiently protects from the summer heat, and in the winter from the occasional cold weather characteristic for this area.

Energy class of stone houses is quite often very low

The biggest problem that owners of such houses are facing is energy efficiencv. All houses available for sale or rent in Croatia must have energy class, what usually raises the price of houses.

Energy class of stone houses is very poor because they are almost never thermally isolated. People who buy them want the stone to be seen from outside, what is impossible with isolation. If you would somehow isolate the stone with a façade, house would get better energy class, but would cease to be “an old stone house”. Buyers look for such houses because of their history, architecture and natural materials they are made of, and their certificate often isn’t important to buyers. However, the law states they must have a certificate.

Non-insulated façades have high energy permeability. Energy class of stone houses can nevertheless be improved if certain rules are respected. There are several ways of decreasing house’s permeability without changing the stone walls: ceiling, doors and windows isolation, and the isolation of walls from inside. This solution isn’t ideal, but it’s effective to some extent – there is a possibility to raise an energy class of the house for at least one level with this.