low-energy houses
Development of low-energy houses is closely connected to the growing costs for energies in the past years. Generally the low-energy houses save half of the costs for heating compared with brick houses. Many highly insulating materials have been developed as well as new building technologies. Low-energy houses in the Czech Republic are in the range up to 50 kWh/m2a. As already mentioned, way to low-energy house leads through good insulating features of used materials. Heat passage coefficient ( U ) stated in W/m2*K, expresses the amount of insulation. The following table shows parameters, which should be reached for each part of the house, if low-energy building is required.
|
Outside walls |
U = 0,2 W/m2 .K |
|
Roof |
U =0,2 W/m2 .K |
|
Floor |
U =0,4 W/m2 .K |
|
Windows |
U =1,1 W/m2 .K |
Important feature of insulating materials is it´s humidity permeability. If the wall accepts humidity naturally originating during the operation of the house, then the insulating features are significantly reduced. For this reason a moisture shield, which prevents the humidity from penetrating into the walls, is used in low-energy houses. The quality of tightness is tested by so called „Blower-door test“ , which measures how long it takes until the inside overpressure in the house drops on the level of the outside pressure.
Penetrating of humidity into house walls can bring e.g. moulds, rust, cracking of render etc.
More information can be also found in section Passive houses or you can contact our Sales Department.
