The Concept


of heating and cooling demand by 90%

A standard social Multifamily House of 750 m2, built in the 70s to accommodate refugees, is about to be refurbished with regard to its energy efficiency according to the Passive House Concept.




The objectives of the refurbishment are the minimization of heating and cooling demand by 90%, while achieving the best possible thermal comfort conditions. Moreover, by installing a small Renewable Energy system, the building’s energy production will overcome the building’s consumption and it will become a Positive Energy Building in the simplest way. In this way, the carbon footprint of the building is going to be virtually eliminated and the requirements for carbon neutral buildings, which will be implemented from 2030 for all buildings, are going to be met today without huge investments in large scale Renewable Energy Systems.


indoor temperature, relative humidity and CO2 concentration for two years

Hellenic Passive House Institute performed the energy balance simulation study in collaboration with Centre for Research and Technology Hellas (CERTH) within the framework of the European Project RINNO. Advanced monitoring systems have been already install in order to measure the thermal comfort and the energy consumption before the renovation. These systems will monitor indoor temperature, relative humidity and CO2 concentration for two years, one year before the renovation and one year after the renovation. The project is targeting not only to create an energy efficient building, but also to increase the quality of thermal comfort to the best possible level.

The multifamily house is set under the auspices of the Hellenic Passive House Institute and the Municipality of Moschato-Tavros for five years with the consent of all the residents, who accept and commit to all the actions required for the project. The results of the project will be used by HPHI for the development of a feasibility study concerning the refurbishment of all the immigrant multifamily and social housing complexes of the surrounding area of Tavros – Moschato – Kallithea – Drougouti. The latter, aims to create new innovative funding schemes to attract investors and companies providing energy services, which will undertake the task of bringing the region’s buildings to NZEB standards in time, under the requirements of the current legislation.

What is a Passive House?

Passive House is a design standard that achieves thermal comfort with minimal heating and cooling by using insulation, airtightness, appropriate window and door design, ventilation systems with heat recovery, and elimination of thermal bridges, which are the 5 basic principles. The concept started from Germany in the 1990s and in 2022 it has been designed, implemented and monitored successfully worldwide. In Greece, the Passive House Concept has been developed and implemented successfully since 2010 through Hellenic Passive House Institute.

What is a Passive House offering?

Quality Assurance! The Passive House concept considered the best in the world concerning energy efficiency in buildings, because through a demanding procedure the actual performance of the building is similar to the theoretical calculations. Following the certification process and using validated software like PHPP, the performance gap between theory and implementation is eliminated.

Key Facts from Passivistas Papagos Project:

The Home Project, implemented in 2015

A single-family house of 150m2 in Papagos, built in 1965 and refurbished according to the PH Concept in 2015. The building needed 3.5 tons of oil for heating which was costing around 3.500€, while the indoor temperature during winter was from 15℃ to 18℃. After the renovation the heating and cooling demand is 10 times less while the indoor quality stands at perfect conditions.



No Performance Gap

The biggest advantage of a Passive House is the elimination of the performance gap between the theoretical study and the measured consumption. In the following diagrams for heating and cooling energy the theoretical and the actual measured consumption is similar, taken average values from 7 years measurements.

Heating Energy

No Data Found

Cooling Energy

No Data Found


Indoor Conditions

A Passive House promises yearly indoor temperature between 20℃ and 25℃, relative humidity between 35-55% and CO2 concentration below 1000ppm. The Temperature range is always between 20℃ and 25℃ independent from the outside temperature.


No Data Found


Indepedency from energy cost

Heating and cooling energy cost are in total 150€ for the whole building in an average measurement of 7 years.

Energy Cost

No Data Found

Get involved and support our cause to improve this residence on "Tavros Project"