Buildings and Their Close Link with Energy and Climate Change
Today, it is imperative to recognize that cities are a catalyst for development and growth, mostly because they concentrate a significant proportion of economic, cultural and social activities, and because they have the best infrastructure and access to basic services. As a result, more than half of the world's population now lives in urban settlements, and this is expected to rise to 68% by 2050. At the same time, cities play a crucial role in the fight against climate change, as they are responsible for 70% of global CO2 emissions, mainly from the transport sector, and the operation and construction of buildings.
It is estimated that buildings are responsible for 37% of global CO2 emissions, of which 10% are direct emissions generated during the construction phase, which includes the production of materials such as glass, steel, cement, etc., and 27% are indirect emissions associated with the transformation and final use of energy in buildings.
In this sense, implementing measures to reduce energy consumption in buildings and promoting the use of on-site renewable energy sources are some of the most effective strategies to reduce the environmental impact of the building sector and ensure that cities of the future are inclusive, safe, resilient and sustainable spaces.
However, the solution is a little more complex if it is considered that not all buildings consume energy in the same way, and that there are social and economic factors that affect access and full enjoyment.
Climate and its Relationship with the Energy Demand of Buildings in Mexico
In Mexico, for example, the residential sector accounts for 15.6% of final energy consumption at the national level, which represents more than 6 times the proportion of energy consumed at the national level by the commercial and public sector (2.9%), which includes the energy consumption of other buildings such as shopping centers, offices, hotels, hospitals, etc., and the energy destined for public lighting, pumping of drinking water and wastewater.
On the other hand, although the residential sector in Mexico distributes its energy consumption nationally between the use of fossil fuels (firewood, LPG or natural gas), electricity and renewable solar energy, there are strong variations linked to the location and climate of the house, both in the type of energy consumed (thermal or electric) and in the payment for energy services (gas or electricity).
Illustration. Final use of energy in the residential sector (Left), Percentage of final use of energy by sector in México (Right).
Source: Balance Nacional de Energia 2023.
Own elaboration, image used for educational purposes.
In this context, it is estimated that more than 45% of the population in Mexico lives in areas where the climate is warm for most of the year, so that in addition to consuming energy to meet basic household needs such as lighting, cooking and food preservation, hygiene, entertainment, among others, they must also seek solutions to achieve thermal comfort in their homes. These solutions can range from the simplest and most intuitive, such as opening a window to create natural ventilation, to the most sophisticated and requiring additional energy consumption, such as the use of Heating, Ventilation, and Air Conditioning systems (HVAC).
To illustrate this singularity, it has been observed that of the 7 million air conditioners installed in private dwellings, 95% are installed in extremely hot and tropical climates, while only 14.9% of dwellings in extremely hot climates have some type of thermal insulation as a strategy to counteract heat gain inside the dwelling, indicating that little or no value is placed on architecture or building design as a passive measure to ensure indoor thermal comfort and reduce final energy consumption.
Illustration. Percentage of Homes with Air Conditioning by Federal Entity in Mexico.
Source: Encuesta de Consumo de Energéticos en Viviendas Particulares – ENCEVI 2018, INEGI.
Own elaboration, image used for educational purposes.
Therefore, it is estimated that households in hot climates spend up to 60% of their total expenditure on energy services (gas or electricity) on paying for electricity, which is directly related to the intensive use of air conditioning during the hot season (spring-summer), while in temperate climates between 50% and 70% of total energy expenditure is spent on paying for some type of fossil fuel (usually LPG or dry gas) to heat water or prepare food.
As a result, households in extremely hot climates spend up to 30% more on energy services than households in temperate climates (CONUEE 2018), which in turn forces end-users to choose between adequately meeting energy-related needs (thermal comfort, food, hygiene and cleaning, lighting, entertainment) or foregoing some other basic need (education, clothing and footwear, transport, etc.).
The Social Dimension of Energy and Impact on Quality of Life
Based on this, the study of the social dimension of energy has gained importance in recent years, given the role that access to clean and affordable energy services plays in improving the quality of life and reducing poverty among the population, as well as the fact that energy is closely linked to all activities of daily life.
One of the main research lines around the world is the concept of “Energy Poverty”, which stems from Lewis's (1982) definition of “Fuel Poverty” as “The inability to afford the fuel necessary to maintain the heat or temperature that provides thermal comfort for the members of a household”. Later, Dr Brenda Boardman narrowed this definition by suggesting that 'a household is in fuel poverty if it spends more than 10% of its income on adequate heating' (Boardman, 1991).
Based on this definition, the National Commission for the Efficient Use of Energy (CONUEE for its acronym in Spanish) estimates that 11% of all households in Mexico (equivalent to 3.5 million households) are classified as “Energy Poverty”, mainly concentrated in the northern border of the country (dry hot climate), where 18% of households (about 1 in 5) have expenditures above 10% of household income.
Illustration. Homes with inefficient or obsolete air conditioners.
Source: Image used for educational purposes
In economic and environmental terms, it has been quantified that the government spends up to 40 billion Mexican Pesos (MXN), or nearly 2 billion USD, to subsidize the cost of electricity for households in hot weather, in addition to the emission of up to 75 million tons of CO2 related to energy consumption in residential and commercial buildings, which represents 12% of total CO2 emissions nationally (CONUEE 2020).
In terms of social implications, the development and quality of life of residents suffering from these conditions can be affected by the fact that they do not have a home that provides thermal comfort inside, which limits the possibility of fully carrying out all activities related to the home, such as resting or studying, which in turn indirectly affects the productivity and economic activity of the residents, reducing their participation in the economic and social development of the locality.
Faced with the adverse effects of this phenomenon, a series of reactive measures have been implemented to minimize its impact on the Mexican population, such as the implementation of a policy of subsidizing electricity consumption, the regulation and labelling of household appliances, particularly HVAC systems, and the financing of photovoltaic systems connected to the grid to compensate for electricity consumption.
Actions and Initiatives for the Development of Sustainable Buildings
Although to a lesser extent, there are also other actions related to the development of sustainable buildings that consider the importance of architectural design as a first strategy to counteract the intensive use of energy for indoor climate control, such as the development and requirement of sustainable building standards and codes, the adoption of national or international certifications for sustainable buildings, or even the setting of targets and objectives as part of national commitments to mitigate and adapt to climate change (Nationally Determined Contributions – NDC).
In Mexico, the voluntary adoption of international certifications such as EDGE from the International Finance Corporation (IFC) or LEED from the U.S. Green Building Council (USGBC) stands out, which have had rapid growth mainly in the residential and commercial sectors respectively. Other trends include the development of national certifications such as the ECOCASA label for residential buildings from Sociedad Hipotecaría Federal (SHF for its acronym in Spanish); the requirement of Mexican Official Standards such as NMX-164-SCFI - Sustainable Buildings, NOM-008-ENER or NOM-020-ENER - Energy Efficiency in Residential and Non-Residential Buildings; and the implementation of financial and fiscal incentives linked to compliance with any of the above measures, such as the granting of green mortgages by private banks, the issuance of green bonds or tax deductions, among others.
Illustration. Different actions related to the development of sustainable buildings in México.
Source: Own elaboration, image used for educational purposes.
In conclusion, although housing as a type of building is only a sample of the enormous variety of buildings that a city contains (schools, hotels, shopping centers, hospitals, offices, stadiums, etc.), its analysis contributes to raising public awareness of the negative effects that buildings can have on the habitability and quality of life of their users if they are not designed, equipped and operated according to criteria of efficiency and sustainability; in addition to the enormous importance of the housing sector in the consolidation and structure of cities, as well as its environmental impact derived from the transformation and use of final energy.
In this sense, buildings, and in particular housing, should be considered not only as a highly effective mechanism for the global reduction of GHG, but also as the first defense and method of adaptation to the adverse effects of climate change, thus ensuring a better quality of life for its residents, which is all of us.