Energy Renovation of a Single-Family House

Around 40% of produced energy is generated for the needs of buildings, which can be reduced through energy-efficient construction. The implementation of measures to reduce heating energy is not limited to new buildings; they can also be effectively applied to existing, old buildings. ** The greatest energy savings can be achieved through quality renovation of the building envelope.** By using the right measures to reduce energy consumption, every building can approach energy-efficient houses. Analyses have shown that ** payback periods for invested money exceed 25 years, which is why many do not find renovations favourable. Of course, simple measures such as ** thermal insulation of the attic pay back within a few years, if we do not consider the cost of renovation.

Problem

Around 40% of produced energy is generated for the needs of buildings, which can be reduced through energy-efficient construction.

Solution and Method

The implementation of measures to reduce heating energy is not limited to new buildings; they can also be effectively applied to existing, old buildings. The greatest energy savings can be achieved through quality renovation of the building envelope. By using the right measures to reduce energy consumption, every building can approach energy-efficient houses. Among the advantages of an energy-efficient building we can count ** higher quality of living** in the renovated building, ** higher air quality** in the building, especially if we use ecological materials in construction, ** lower energy consumption** for heating and thus also ** lower costs, and ** reduction of CO2 emissions.

The author in the diploma thesis investigated the problem of a wasteful building, where despite thermal insulation being installed, heating is the largest energy consumer. As concern for the environment and dependence on non-renewable energy sources grows over the years, countries are fighting this by raising the standards that buildings must meet. Thus, on 1 July 2010, a new regulation came into force in Slovenia governing the field of design, construction and maintenance of buildings – ** PURES 2010**. The regulation was adopted on the basis of requirements prescribed by the European directive on energy performance of buildings.

The directive requires member states to set minimum requirements that new and existing buildings must meet, regulate the calculation of energy performance of buildings, energy certify buildings, regulate regular inspections of boilers, climate systems, etc. Heating accounts for up to 60% of energy, the remaining energy is consumed for heating sanitary water, cooking, lighting and household appliances. Heat losses in building heating cannot be stopped, but they can be ** significantly reduced by improving thermal insulation**, which was also proven in their case. When designing a home, we strive to create a space that will achieve thermal living comfort with the lowest possible use of heating energy.

Thus, with renovation of the building envelope that he analysed, the annual energy consumption for heating would be reduced by 23%. With calculations before and after renovation, he calculated that the set goal, which was 30%, was not achieved. Despite not reaching the goal, he came quite close to the figure and ** proved a reduction in the energy required for heating the building and thus also the costs of energy supply.** Per heating season, their building consumes 28,060 kWh of energy to maintain a constant temperature in the rooms (24°C).

He reduced this figure through the presented renovation to 22,814 kWh, thus obtaining a difference of 5,246 kWh. If we divide this difference by the daily energy consumption, we can calculate the number of days for which this difference is sufficient to maintain a constant temperature in the building. Thus, with a consumption of 230 kWh we get 23 days, and with a consumption of 187 kWh we get 28 days.

We get a difference of 5 days, which means that compared to the old state, after renovation we can live in the house with free heating for 5 days. He calculated that the saving from reducing the required energy from 230 kWh to 187 kWh would be from €110 to €440 per season. The cost of purchasing heating oil would pay back in 50 years, and for purchasing firewood in 200 years.

This figure is indeed enormous, but in their case, where they heat with domestic wood, i.e. they get it for free, this saving would also be noticeable. This number could be higher if they approached renovation with construction measures – replacement of windows, doors and similar. For better ** utilisation of solar energy, window surfaces on the sunny side could be increased, thus also contributing to heating living spaces. ** Energy sources are increasingly expensive, so they are forced to think about the greatest possible energy independence. Thus, when renovating the envelope, they could also consider installing a new central furnace for wood biomass.

Since Slovenia is the third most forested country, we should think in this direction and exploit the benefits that our homeland offers us. Despite the large forest coverage, Slovenia still has one of the lowest rates of utilisation of wood biomass for energy production. Renewable sources are also an important source of energy.

They are environmentally friendly and energy production from them leaves no waste, which is why nowadays much thought is also given in this direction. In energy renovation, we can use one of the renewable energy sources. The most suitable to the author seems to be the use of solar energy.

Since we live in Goričko, where there are many sunny days, we can take advantage of this and install solar collectors on the roof. With the help of photovoltaics and other elements, we can very effectively use solar energy for heating and cooling spaces, daylight, cooking and hot water.

Results

Analyses have shown that payback periods for invested money exceed 25 years, which is why many do not find renovations favourable. Of course, simple measures such as ** thermal insulation of the attic** pay back within a few years, if we do not consider the cost of renovation. The latter represents a large expense for owners, but we also notice considerable savings in the supply of required energy.

Therefore, energy renovation should be assessed from the perspective of additional investment for improving the thermal protection of the building.