Heat consumption of low-energy houses does not exceeds 50 kWh/(m2a). Such houses provide noticeably higher standard of energetic effectiveness than the minimal standard required by national regulations for properties of buildings. Usual consumption of a low-energy building is half of energy than consuption of a conventional house.
Principles of a low-energy house:
- It is heated by a heating system with a lower output power and utilises renewable sources of energy.
- Windows of the main residential rooms are oriented to south.
- It has controlled ventilation and provides sufficient air replacement with minimal loss of heat.
- It shows good thermal insulation parameters of all jacketing structures (peripheral walls, windows, floors and ceilings). The desired heat diffusion U of the peripheral structure is from 0.16 to 0.25 W/(m2K).
- Windows with double or triple glazing show excellent thermal-insulation properties.
Parameters for low-energy houses are specified by standards TNI 73 0329 (for family houses) and TNI 73 0330 (for residential houses).