Krivaja low-energy houses are carefully designed and manufactured to the highest level of comfort while having the minimum energy requirement for heating, lighting, etc. That is achieved with a high level of thermal insulation, an air-tight shell, a controlled fresh air ventilation system and by maximising the use of free solar gains through good design. The heat recovery ventilation system and high-quality doors and windows are part of a very low-energy house "package".
Annual heating requirement for low-energy houses is between 15 and 50 kWh/m2. They are just slightly less energy-efficient than passive houses, but the initial construction costs are much lower, and the investment pays off sooner.
Checklist of a House's Energy Efficient Factors
Use energy efficient windows (e.g. Futura 96, Natura+ 96)
Make the house airproof and ensure sufficient ventilation
Minimize thermal bridges
Use a ventilation system that is equipped with good heat retention
For extra points
protection against overheating risks in summer
Pay attention to the energy efficiency of lights and electrical devices
Use renewable energy source (e.g. solar energy)
Design and orientation of the house should be carefully considered