While across Europe they continue extreme heat, a local news story from Lyon, France, went relatively unnoticed.
Namely, in Lyon, Mayor Gregory Duse, at a press conference held on July 15, announced a plan to include the issue of high summer temperatures in the assessment of housing, because it is a "public health problem".
What does that mean? For example, if it is established that the apartment is unconditioned from the aspect of summer thermal comfort, first of all through excessively high temperatures during the day, the implementation of construction measures could be ordered in order to improve that aspect of comfort. Dr. Bojana Zeković writes for the Klima 101 portal.
As announced, the establishment of this practice will also be observed at the national level. This is a national issue for France, which has survived several heat waves since May this year, during which a number of temperature records were broken across the country.
But it is not just a national issue for France. Like France, Serbia also belongs to a large group of European countries where, unlike the comfort during the winter months, the summer heat is simply not the subject of special attention in the field of construction.
Thermal comfort limit
This fact is clear even at the semantic level.
When analyzing the regulations of most European countries in the field of energy efficiency, usually the reference area is taken as the so-called heated area of the building, so the annual energy needs are also expressed per unit of heated area.
Although the term "heated surface" has become established, it also implies a surface that needs to be cooled in warmer seasons. It is an area where, for the sake of people's comfort, uniform levels of thermal comfort are insisted on, i.e. limits of 20 to 26 °C throughout the year.
However, although the upper limit of comfort is 26 °C, there are a large number of apartments that are almost impossible to cool to that limit in the summer, sometimes even with the existence of cooling devices, most often due to the unfavorable orientation of the apartment, the absence of the possibility of cross ventilation as well as appropriate systems of protection from the Sun, or insufficient quality of the thermal envelope, i.e. walls and roof.
It may be intuitively clear to us how unpleasant it is to stay in such a building, but we are not sufficiently aware of the serious health risks of long-term exposure to such conditions: for example, the combination of high heat and tropical nights has disastrous consequences for heart and other chronic patients, due to the inability of the body to properly rest during the night.
The black balance at the end of every heat wave in Europe, including Serbia, is measured in tens of thousands of those who could not cope with it. And a large number of these cases were also affected by inadequate living space.
However, rarely can tenants, based on such problems, challenge the conditionality of housing.
For the sake of comparison, imagine a situation where it is impossible to reach the threshold of winter thermal comfort in a residential or commercial building during the heating season, i.e. a temperature of 20 °C - in that case, there would be a clear basis for complaints and emergency interventions.
Summer comfort and the risk of heat stress
In Serbia, there is a clear lack of regulation that deals with the issue of summer comfort.
According to the "Amendments to the Law on Planning and Construction" from 2023, individual air conditioners are no longer allowed on facades, and the systemic solution to this problem is present almost exclusively on new buildings, which are often built with special niches intended for air conditioners, either on the facade or on the terraces. For existing buildings, that is, existing apartments, an adequate and affordable solution to this problem has not been systematically solved.
Also, according to the "Regulations on energy efficiency of buildings" from 2011, buildings must have blinds on all facades except the north... But their efficiency has not been checked by calculation, because the energy required for cooling is not yet included in the calculation of the required energy, on the basis of which buildings are classified into energy classes!
Although modern buildings are designed and built with efficient central heating and cooling systems, the percentage of these buildings is small compared to the existing building stock. So for the majority of the population, the only solution remains an air conditioner - if they can afford the device, maintenance and increased electricity bills, and if the air conditioner can even bring the living space within the limits of comfort.
Of course, you need to have the right perspective when it comes to cooling as well as heating.
We will agree that in our climate it is unrealistic to expect that we will be able to completely avoid the use of heating in the winter. passive measures - such as a high-quality thermal envelope, solar gains, heat recovery... It is also unrealistic to expect that we can avoid the need for an air conditioner through appropriate design and construction measures, such as sun protection or improved natural ventilation.
But, just as passive heating measures are an important factor in designing a comfortable apartment, so the use of air conditioners must not be the only proposed solution for surviving the increasingly frequent summer heat waves!
A social problem that requires solutions at the level of society
This becomes especially clear when the context shifts from the individual apartment to the wider society.
The summer peaks of energy consumption in Serbia approached the winter peaks, and today they represent a serious challenge for the energy system. Since these new maximums often coincide with periods of heat waves and major droughts, in addition to the issue of thermal comfort for citizens, the rationalization of energy consumption must also be considered.
Also, the problem of summer comfort is related not only to the way we build individual buildings, but to the way we plan and build entire settlements and cities.
Imagine a building in a less built-up environment, rich in lush vegetation with branching canopies and paved with porous materials; this building will have much less problems with achieving suitable summer comfort conditions than the same building in a densely built city core, without surrounding vegetation and with soil clogged with non-porous surfaces.
The reason for this is the heat island effect, which is mainly contributed by intensive construction, the reduction of dense vegetation and green areas in direct contact with the ground, as well as the increase in the percentage of so-called non-porous surfaces.
In many cities of Europe and the world, there are also "patches" to the wider problem of lack of thermal comfort, especially when it comes to the vulnerable population: the relocation of residence, work and gathering activities to public facilities that have been temporarily declared "climate shelters" such as churches, museums, cinemas, and which become day care centers for the reception of those whose thermal comfort is at risk, and thus their health.
However, the long-term key to this problem is not one-time and quick solutions, but adaptation to the conditions of temperature extremes that will become more and more frequent, through a radical change in the paradigm of designing, planning and building cities.
