Passive House KOFINAS

Based on the needs of the modern era for energy saving, at KOFINAS Prefabricated Houses we follow construction practices of reduced energy consumption. Our constructions have been distinguished according to the Energy Performance of Buildings Regulation (KENAK) as energy class A residences, while our guarantee is the building model, the so-called “Passive House” KOFINAS.  

What is a Passive House? 

A passive house is a house that meets all the requirements to be fully energy efficient and environmentally friendly. Specifically, a Passive House offers high energy efficiency, economy and sustainability, with minimal energy requirements and costs for heating and cooling. 

According to the official definition by the German Passive Building Institute, “A passive building is a building in which the indoor thermal comfort (ISO 7730) is ensured exclusively by preheating or pre-cooling the amount of fresh air required (DIN 1946) for the correct indoor atmosphere, without the use of additional air recirculation.”

The company KOFINAS Prefabricated Houses, as an official member of the Hellenic Passive House Institute, is active in the design and construction of Passive Houses with the corresponding official institutional certification, combining the company's quality constructions with sustainability and comfort data!

What are the advantages of a Passive House? 

Energy Efficiency 

Through the passive heating and cooling system, the Passive House has the ability to maintain the correct and desired temperature inside throughout the year, regardless of the climate zone in which it is located. The fact that a Passive House uses alternative heating and cooling methods, such as solar energy, internal heat sources, natural ventilation, etc., makes conventional heating and cooling sources that consume huge amounts of energy completely meaningless and inefficient. The precise design, the appropriately selected materials and of course the modern passive heating and cooling systems, offer each resident / user of the house the best conditions for healthy living without humidity, ensuring a constant temperature. 

Viability 

The Passive House works by limiting heat losses and ensuring heat gains. Due to the bioclimatic design of a passive house, the percentages of energy consumed in a year are clearly reduced compared to the data of a conventional house. In reference, the energy required for heating and cooling in a Passive House is up to 90% less. Due to this, the emissions of pollutants that drastically affect the greenhouse effect are significantly limited. Thus, choosing a passive house can be characterized as one of the most sustainable building and living options, with a low environmental impact, since the primary energy used is extremely small. 

At the same time, it is important to mention that compared to a conventional house, the additional energy required to achieve heating and cooling of a Passive House is negligible if we consider the savings data they offer. Specifically, according to the EIPAK, “in a passive house, less than 1.5 liters of oil or 1.5 cubic meters of natural gas are required per year to heat one square meter of habitable space.” 

Economy 

In a passive house, the savings are obvious from the start of living. The minimal energy requirements reduce to the maximum the necessary operating costs, which, unlike in conventional houses, reach heights both for heating in the winter and for cooling in the warm months. 

At the same time, what is certain is that each tenant / user does not need to worry about unnecessary expenses or about when the initial investment will be fully amortized, since the cost of a passive house is extremely affordable. Specifically, at the company KOFINAS prefabricated houses, the cost of using the highest quality building materials and constructing a passive house is immediately balanced by the reduced operating costs and long-term energy efficiency. 

Comfortable living 

As stated in the official definition of the Passive House, the main result and benefit of passive cooling and heating systems is to ensure a healthy and proper indoor atmosphere. Indeed, due to the way these systems operate with air filtration, automatic humidity regulation, prevention of mold and the damage it may cause, the atmosphere inside a passive house becomes the most suitable for optimal living and excellent quality of life. The fact is that the passive house contributes to the health of users while at the same time constituting an absolutely practical and quality choice, since it does not require constant intervention for ventilation, heating, cooling, hot water, etc. 

What are the basic operating principles of a Passive House? 

The way a Passive House is based on 5 basic design and construction principles, related to the exploitation of the free energy and heat offered. 

In more detail, the so-called “free” heat is produced primarily by the electrical appliances used daily in a home. In order to enable the direct utilization and reuse of this heat, for the purpose of the desired heating, the passive house must follow the following 5 specific operating modes: 

Insulation  

As mentioned, the heat produced by electrical appliances can be retained within a passive house and thus reused for heating purposes, without unnecessary energy requirements and losses. To make this possible, it is necessary to ensure the complete insulation of the house, so that the building shell is completely airtight to retain heat inside during the winter months and to prevent it from escaping during the summer. 

Window frames 

The quality frames of a passive house play an equally important role in its maximum energy efficiency. Specifically, windows with an insulating design, equipped with low-reflection glazing, are absolutely essential to prevent heat from entering or leaving.  

Airtightness 

In a passive house, maximum airtightness of the entire structure is provided in order to minimize potential leaks through openings and thus increase energy efficiency levels. 

Absence of thermal bridges 

With the correct and careful insulation of the entire passive house, the goal is the absence of thermal bridges that are often responsible for the development of moisture, mold and corresponding damage. This creates the conditions for comfortable living, in a completely hygienic atmosphere and a safe environment. 

Ventilation 

A key factor in the operation of a passive house is, of course, the ventilation systems that are incorporated for maximum energy efficiency and the regulation of the air, humidity and heat that enters the interior of the building. 

Practically, how does a passive house work? 

1. A ventilation system with an air-to-air heat exchanger is installed so that it can simultaneously bring in fresh air from outside and simultaneously extract a quantity of stale air from inside the building.

2. In the winter months, the cold outside fresh air enters the exchanger, receives the heat of the exhausted stale air and enters the passive house. Specifically, the warm stale air leaving the house “carries” the “free” heat, which through the exchanger heats the fresh air entering the house.

3. In the summer, the exhausted stale air cools the warmer incoming fresh air, maintaining appropriate cooling levels inside the home. 

4. In case the above system is combined with geothermal energy (the clean air is first diffused from the earth and then goes to the exchanger), the profits and general energy benefits are multiplied both in winter and summer. 

As a result of all of the above, the installation of a conventional heating and cooling system can be avoided and the house can operate fully efficiently through mechanical ventilation systems for ultimate energy efficiency. 

What is the cost of a Passive House? 

Based on the data and specifications of the company KOFINAS Prefabricated Houses, it is important to mention that the cost of a 100 sq m passive house is approximately 10% higher than that of a typical construction of our company.

This difference is obviously insignificant when compared to the long-term savings that a passive house offers due to minimized operating costs, since the payback is immediate and the benefits become apparent from the very first moment, both in terms of energy and financial performance. 

Certification of the company KOFINAS for the Passive House 

A basic requirement for a house to be classified as Passive is to test all its functions in practice to check whether it meets the basic principles of how a passive house is organized.

The company KOFINAS, which has proven to be extremely interested in the scientific certification and guarantee of all the practices and technologies it utilizes, has undergone the Passive House certification process. 

The certification criteria for passive houses are determined by the Passive House Institute, which is based in Darmstadt, Germany.

After a series of analytical scientific tests, it was proven that the KOFINAS company follows all the necessary design and construction standards of the passive building, in order to provide all the energy and practical benefits to its customers. 

Are you interested in building your own? prefabricated house according to the best and highest quality standards on the market? 

The company “Kofinas” is certified by Greek and international bodies for all the materials it uses as well as for the manufacturing process it follows.

In this way, our consistent quality and reliability are proven, which characterizes every “Kofina” construction from 1977 to the present day.

Contact us, and we will take care of it. prefabricated your dream home a reality.