Three quarters of Czech homes have partial insulation; comprehensive insulation would save more energy

Three quarters of detached houses in Czechia built before 1970 have partial insulation. The lack of comprehensive insulation significantly reduces the effectiveness of other energy-saving measures, even though it could cut energy consumption by up to three times. Most partially insulated houses have had their windows replaced with thermally insulating glazing. One in four detached houses has an insulated roof, while 30 percent have insulated walls. These are the findings of an analysis by the data journalism portal Czechia in Data, which ČTK has seen. According to the analysis, comprehensive insulation of a medium-sized house can cost more than half a million crowns. Among other benefits, it also reduces emissions. The Ministry of the Environment (MŽP) has previously allocated subsidies for insulation through several programmes.

„While all detached houses built after 2015 have at least some insulation, according to the Czech Statistical Office’s Energo 2021 survey, 26,3 percent of those built before 1970 have none. There is still scope for renovations that can significantly reduce energy consumption for heating, despite the long-term decline in the share of insulated detached houses. Between 2015 and 2021, it fell by approximately five percentage points,“ said Milan Mařík of Czechia in Data.

According to Pavel Zemene of the EPS ČR association, comprehensive insulation of a medium-sized detached house with an area of 150 square metres can cost around half a million to three quarters of a million crowns, depending on the building’s condition, options and specific details. Marta Gellová, director of the professional association Šance pro budovy, added that a comprehensively insulated detached house of the same size heated by gas consumes a maximum of 12 megawatt-hours a year. An uninsulated detached house with the same floor area uses an average of 40 megawatt-hours a year for heating, three times as much.

Installing a photovoltaic system can cost around 400.000 crowns, according to the analysis, although costs can again vary from house to house. For example, ČEZ lists 200.000 crowns as an indicative lower limit for the investment. The cost of a heat pump depends primarily on the technology chosen, but runs to several hundred thousand crowns.

Roof-window manufacturer Velux said in its analysis that insulation also helps reduce the volume of greenhouse gas emissions. Citing Eurostat data, it said emissions caused by the burning of fossil fuels in Czech households have fallen by 19 percent since 2010, although the EU average is a further quarter lower. Households are responsible, for example, for 23 percent of total sulphur dioxide emissions.

In January, the Ministry of the Environment said it would increase support under the New Green Savings (NZÚ) programme, which provides funding for basic or partial insulation. The Renovate Grandma’s House programme is also intended to support comprehensive insulation of houses and apartments. Applicants receive part of the money upfront as a non-repayable subsidy and borrow the remainder at a preferential interest rate of 3,5 percent. The loan amount is updated every six months and can be up to twice the amount of the subsidy.