Construction company KREOS invests in new technologies and constructional materials providing for optimum electric effectiveness and maximum longevity of a house. We have for an object to invest in conceptions of the future such as construction of low – energy and passive houses. A low – energy house has an extremely low consumption of energy. A passive house does not need an active heating system. That considerably reduces the consumption of energy and provides complete comfort throughout the year.
Our energy-saving houses are built of high quality natural materials – wooden bearing structure and plaster hardboard plates for interior and exterior walls. The walls are multilayered framework with filling of heat- and sound insulating materials. The insulating material is mineral wool – glass or stone. The foundations and basement rooms are made of reinforced concrete. They need to be insulated from the damp and cold earth. Each constructive element – from foundations to the roof is separated from the surrounding temperature influences by insulation of good quality.
Good energy – saving indexes are achievable when we reconstruct reinforced concrete buildings.
The most important criteria for passive houses are:
* perfect insulation of walls, ceilings and floors;
* lack of thermal bridges;
* lack of airlifts;
* comfortable ventilation.
Comfortable airing:
* a person needs 30 cubic metres of fresh air per hour with normal activity;
* the modern ventilation systems are up to the requirements of increased comfort and provide irreproachably clean air on the premises;
* less pollution with dust;
* lack of the injurious to health pollen – comfort for people suffering from allergies;
* odours and cigarette smoke are sucked out and not spread all over the house;
* lack of air current.
We have for an object to achieve high indexes of electric effectiveness when we plan and execute our buildings. It will not be long before buildings in Bulgaria are classified depending on the criteria of low – energy structures. A number of European countries have developed governmental programmes which help the construction of low – energy houses. Future prognoses are that a family consumption of energy for heating, hot water and household appliances should be up to 120kWh/m2 per year. Fuels are running out and get up again and again. There are noxious gases in the atmosphere because of the combustion of the fuels. They pollute the environment and accelerate the greenhouse effect. Mankind uncovered the renewable energy sources: hydropower(water), solar, wind, geothermal and biomass.
Passive house is the highest class energy-saving house. It uses only renewable energy sources for heating. Houses which are less energy effective use gas boiler or other type of fuel. Low – energy houses dispose of mechanical ventilation system which provides perfect microclimate and healthful conditions for the residents. This ventilation system blasts fresh air into the main dwellings and sucks out the polluted air from kitchen, bathrooms and all other room with significant air pollution. The ventilation would be controlled by central air condition system – recuperator. This system warms the fresh air using the heat of the polluted air.
Construction company KREOS follows the requirements for energy effective joinery, window panes and density of the construction casing. The windows (both joinery and panes) have coefficient of thermal conductivity k<0.80 W/m2C and solar agent about 50%. The air flowing through untight slits do not exceed 0.6 times of the inner volume of the house per hour.
Low energy houses with wooden construction and multilayered walls are energy saving and ecological in another aspect – the production of the material for building a wooden house needs less energy than that of a monolithic one.
The KREOS’s houses use different building systems – faced with plaster hardboard plates external and partition walls, hung ceiling, double floor. Exterior walls could be faced with many kinds of materials – natural stone, wood, bricks and particular panels. That is a multiform construction technology.