On average, houses including those in the tropics are responsible for almost 39% of the global carbon emission caused by non-renewables, first and foremost by fuel. Looking at the worldwide map of residential buildings’ contribution compared with commercial, the worldwide national maximum of 33.5% CO₂ of housing is caused by residential buildings in Uzbekistan. In an overwhelming number of most countries, their values are significantly lower, due to comparably lower energy demand than commercial buildings and because affordable homes increasingly use small PV to cater for their own basic needs. However, with the rising temperature and a likewise growing imperative to cool homes from about 30 °C onwards basically by split-unit air conditioners, the residential houses’ portion of CO₂-emission might dramatically increase to survive such more common hot periods in the future. In combination with air conditioners needing some airtightness, the first purpose of this entry is to show that bv 2050 in tropical regions, there will be no alternative to relatively airtight houses if the temperatures rise at the present speed. This is one alternative to an uncontrollable and life-threatening migration of millions of people to cooler but still livable regions in 2050. To trigger necessary changes toward homes that can better avert the heat, using the method of qualitative comparative content analysis, passive houses (PH) have emerged as adaptations to the tropical climate. Therefore, the second purpose of this in-depth study with the perspective of social science, is to reveal a comparative closer qualitative look at the tropicalized PH-approach. It is probably the most civilized building energy-saving strategy on the planet and can systematically keep the threatening increasing heat outside. However, before utilizing the concept, herein need to investigate why PH-technology as a whole concept with all its modules discussed earlier has been very slow to “go South” into the tropical region (the original PH will be referred to as “PH1”). The reason is that some qualitative differences of the more affordable and more simplistic tropicalized “PH2” make it easier and more realistic to penetrate the market, without letting go meaningful R&D-insights of PH1. As a probably facilitating future solution, the result is the triple-tabled option to utilise more synergies between the usually closed PH1 and the more open and flexibly naturally ventilated PH2. Unlike the PH-platform, ZEMCH is a related concept which tries to cater specifically to the significantly growing market for lower-income homes to go for carbonless energy. The conclusion is that scaling for residential buildings as mass products using passive house technology in combination with ZEMCH could turn out to become an important topic. It comprises the question in how far low or no carbon affordable homes based on the PH-concept in combination with ZEMCH-applications also may come into play as standard and to help mother Earth’s struggle for survival.

The background of this novel study is how to apply an empirically adjusted Passive House concept in the tropics - beyond its otherwise prevailing global standards. Even though well-insulated houses have been on the planet since people settled down in some of their first dwellings, passive in the 21st century is different. It includes strict rules for airtightness and fitting of windows along with a sophisticated concept for artificial ventilation. Fresh air reachable from outside by filtered ventilation with heat recovery describes the heart of the system - if natural outside air is not preferable, it is convenient just in seasons with thermal comfort. Hence, the purpose and aim of the study presented here is to use a less common and at the same time more cost-saving approach: It might seem that the modern type of passive house entails the same standards that have been developed firmly on its own global market niche. However, this article tries to contribute toward a new development of modern passive homes for low-cost affordable tropical and subtropical houses in their entirety. As a concluding note, the author states that nobody has ever disproven this evolving concept as a combination of airtightness and a new way of forced ventilation without heat- or coolness recovery which is highly applicable for low-cost residential areas in tropical countries. By generating lower temperatures, it can help to surpass the overheating caused by climate change in certain tropical climate zones in higher altitudes and during cooler seasons. The condition is that the occupants are willing to accept a thermal comfort of up to 28 °C and humidity in its 70s and 80s.