Low-energy or passive house

327More and more people deciding about construction of family house consider energy saving house, understand buildings, which use way less energy for heating than classic houses. Let´s be honest here, reason is not only ecological and respect towards nature, even thought this side of issue is serious. Last but not least is significant and quicker financial return of  low-energy of passive house. And this really worth for thought, right?

Low-energy family house

Low-energy family house is higher category of standard family houses. Investment into this kind of house is higher comparable to standard house. The main difference is year amount of energy used for heating. As low-energy house is considered as building with maximal year heating  energy  of 50kWh/m2  . Fundamental design principles of low-energy houses are defined by proper shape and disposition solution in given spot. Living areas should be orientated to the south, to gain as much solar energy as possible. Important step is thought about house construction, and parameters of walls and roof. Cover construction of the object should have great thermal-insulation characters and construction details of the building shouldn´t create thermal bridges R = 5 m2 K W-1 and more. As well we should keep in mind right choice of the windows with good shading. Concept of this kind of the house comes from idea to use all available resources from house surrounding  (heat pump). Between technical house equipment belongs convection heating, heat recovery, solar cells and a fireplace. Very important factor for designing is interconnection all of them into the whole.

Energy passive house 

Energy passive house is the higher category of energy saving buildings. Investment into EPD is higher that low-energy houses. Main difference between them is energy spend for heating. Passive house spend maximum 15kWh/m2 per year. These houses don´t need active heating system and most of the energy they spend, they get from  inside thermal sources, solar energy, geothermal energy. Energy difficulty of pasive house is  90% less than standard house. Internal thermal comfort is possible to reach without classic heating system and air-condition thanks to passively gained solar energy and additive heating. It is necessary to have air-tight house cover including sufficient thermal insulation, windows with triple glazing and special frame, system providing regular air exchange and water heating and quality finish of technical details without thermal bridges. Whole energy necessity for heating, domestic hot water preparation and operation of all electrical appliances in energy passive house doesn´t exceed  120 kWh/m2 per year.

Criteria of Energy Passive House:

 1. Compact building cover with quality thermal insulation

Necessary condition in low-energy and passive houses is the fact, that used materials should meet criteria of thermo-technical regulation, as well as criteria of building tightness. In case of concrete, stone, either brick it doesn´t mean only thick external walls, but also tens of centimeters of thermal insulation. For passive houses is counted with extra 30 to 40 cm of insulation. That means that thick walls significantly degrease useable internal area. Moreover, it raises the budget. This is reason why with family houses works system of whole construction systems e.g.  VELOX, DIFU...

2.South orientation of main facade in case of passive house

3. Right glasss and window frame, precise window and door assembly

 4. Air-tightness of energy passive house and perfect wind-tightness, heat accumulation in the winter, cold accumulation in the summer

5. Controlled ventialtion with heat recovery and fresh air heat, air pre-heating and heating of indoor air by sunlight

Technical equipment of low-energy and passive houses 

-Controlled ventilation

Controlled (managed) ventilation with recuperation (heat recovery from outgoing air) is necessary condition in service of passive houses. It  provides exchange of air in whole building, heat recovery in return and heating (cooling) air in the ground collector.

-Thermal pump

Use of thermal pump is necessary to reach standard of low-energy and passive house, even thought in most of the cases it is used to preheat a hot water, but also for low-temperature heating. As source of heat is possible to use well or ground exchanger. Principle of thermal pump is closed cooling circuit (similar as a fridge), as heat on one side remove and on the other side submit.  Thermal pump can be removed from surrounding air, exhaust air, surface water, ground, wells and groundwater.  Available source is exhaust heat used previously in technological processes. Type of heat pump is determined based on cooling and heating substance. The most common combination is air/water,air/air or ground/water. To preheat  hot water in family houses are available on the market affordable compact thermal pumps. The hot-air heat pumps often use the optional reversing fan - in the winter mansion, summer air in the room cools. These systems are spread among office spaces.

-Sun collectors

Sun collectors are nowadays common technology. Solar equipments are used mostly in new buildings, but also their number is increasing in refurbishedbuildings. Solar panels are required equipment of low-energy and passive houses, as they significantly help with energy bilancy. If their use is designed wisely they can save 60-80% of money spend for water preheat.


-Low-energy house is a cheaper version for those, who plan future low cost for heating, water heating-up, ventilation and prioritize thermal comfort as well as health of residents

-Passive houses comparable to low-energy houses are more expensive, but on the other hand in terms of energy markedly self-reliant. For owners the only criteria doesn´t need to be ratio"price/performance" and economy return. As well there is a  demand on stricter adherence to the rules and flawless execution of all technical details comparable to low-energy houses. Passive house doesn´t need conventional heating or air conditioning, and its power efficiency comes mainly from natural resources.

- If you will choose any of them, we can confirm you made a good choice. You decide for healthy house saving nature, energy, health, and after couple of year your initial investment will start to return.So let´s have a look at our portfolio, where you will find a lot of low-energy houses and please do not hesitate to contact us. We will take care for the rest.

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