In single-family housing, increasing emphasis is being placed on reducing energy consumption. Of course, the largest percentage of it is thermal energy necessary to heat it, so it is not surprising that the energy efficiency of the house is determined primarily by its tightness and thermal insulation. However, the factors influencing energy consumption do not end here, so it is worth mentioning air conditioning, domestic water heating and lighting. If you are looking for a way to reduce your energy consumption in any of the above cases, it's worth betting on energy-efficient and passive houses.
Energy-saving house and its characteristics
When we talk about an energy-efficient house, we mean a building that guarantees an energy consumption of 40 kWh/(m²/year). This is really not much, especially if we consider the fact that in a classic house of several years old, the consumption is even 150-200 kWh/(m²/year). It is also assumed that such a house should have as few bendings of external walls and roof slopes as possible. Building on a compact building is not accidental at all, because it is characterized by the fact that there are not so many surfaces through which heat can penetrate.
Not without significance, moreover, is the insulation itself, which characterises the external walls. In this case, the focus is on really thick layers of thermal insulation made with both glass wool and foamed polystyrene. Good insulation should not be forgotten, even when we are interested in doors and windows. They themselves should be made with great care in order to eliminate the phenomenon of thermal bridges, i.e. these leaks, which very often occur in places where the wall is connected to the window frame and balcony slab.
Speaking of an energy-efficient house, we should not forget about not only efficient but also nature-friendly installations. Examples include heat pumps and solar collectors used to heat domestic hot water. An interesting solution is also a mechanical ventilation system with heat recovery, which can be an alternative to gravity ventilation.
Passive house and its characteristics
A passive house attracts attention because it guarantees an energy consumption of 15 kWh/(m²/year). Its characteristic features are, among others, a square or rectangular outline, no folds and a flat, desktop roof. This minimises the surface area of these partitions, through which heat can pass. When choosing a passive house design, it is also worth to pay attention to the insulation of door and window frames. Moreover, the windows themselves must be arranged on the façade of the building in a well-defined manner. It is important that the house is positioned in relation to the directions of the world, so large glazing areas should be located primarily in the south, which will make it possible to obtain so-called passive solar gains. This is where the daytime living rooms are to be located. The north side is the most common place in passive houses where toilets, storage compartments and wardrobes appear.
A passive house is also a space that cannot do without a heat pump and mechanical ventilation with heat recovery. The installation of a solar collector is also something almost obvious. In the case of both energy-efficient and passive houses, we can talk about a considerable challenge, but we cannot disagree with the fact that we are dealing with a profitable investment. Saving energy means taking care of the environment and taking a more progressive approach to architecture. The choice between the two types of houses is usually dependent on our financial capabilities, although aesthetic preferences also play a role. Passive house is a much simpler form, but sometimes it turns out to be a more expensive solution than its energy-efficient equivalent, because it is associated with the need to equip it with expensive installations and ensure a high degree of insulation. Even before making the final choice, it is worthwhile to prepare a balance sheet of profits and losses, as it will facilitate the decision, which will not be regretted later.