In the middle and end of May 2026, Western Europe witnessed an unusual summer heat wave, characterized as a spring anomaly with July intensity.

These temperatures resulted in record-breaking readings across all three countries for the month of May, running 10 to 15°C above historical averages for the period, according to data from the EU's Copernicus Climate Change Service.

Two weeks after the May heat wave, the World Health Organization launched the second edition of the Heat–Health Action Plans Guidance, at a press conference held at Germany's Federal Ministry for the Environment. The first edition had been published in 2008.

The document presents an updated framework with eight core elements:

The stated objective is to stop treating heat waves as isolated emergencies, and instead address them as a recurring climate risk requiring the redesign of cities, workplaces, and health systems.

Hans Kluge, WHO Regional Director for Europe, presented the following figure: more than 200,000 people died from heat in Europe over the past four years, and the agency's statement made clear that nearly all of those deaths were preventable.

According to the European Environment Agency, Europeans spend between 80% and 90% of their time indoors.

When outdoor temperatures rise, the thermal performance of a building determines what its occupants feel, and most of the existing building stock was designed for a climate that has changed: cold winters, mild summers, and little need for cooling.

Only 20% of European buildings have air conditioning, because those buildings were never designed with that need in mind. Thermal insulation, where it exists, was specified to retain heat in winter, not to block it in summer. Wide windows and glass facades are choices that worked well in temperate climates, but have become solar heat traps during 35 to 40°C heat waves.

Installing air conditioning at scale addresses the immediate symptom, but creates other problems: high energy consumption, more emissions, and more heat discharged into already overheating streets.

The approach recommended by the WHO and the World Resources Institute points in a different direction:

These are design decisions, not retrofit solutions.

According to the International Energy Agency, adequate insulation and external shading can reduce a building's cooling demand by up to 80%. Well-designed natural ventilation can also lower indoor temperatures by up to 9°C.

Europe is warming at roughly twice the global average rate. Heat has historically never been central to European urban planning or building codes, as the focus was always on winter performance.

That misalignment between the climate of the past and the climate of the present is the core mechanism of the problem. Europe's existing building stock was not designed for what it is experiencing now. And the cost shows up in the mortality data.

Most projects decide orientation, glazing, and shading without running a single simulation. The result shows up in the first summer: overheated rooms, air conditioning running all day, and clients complaining.

Thermal comfort gets decided in the first weeks of a project, with data, not intuition!

That’s exactly what UGREEN Pass’s dedicated module covers, with simulation applied across different climates.

The content includes ASHRAE 55 for thermal comfort, climate reading with Climate Consultant, and full simulation in OpenStudio and EnergyPlus, from modeling through scenario comparison.

Designing without these simulations can get expensive later!

Get UGREEN Pass now for US$ 397/year or US$ 847 for lifetime access, and you’ll unlock this module plus 7 more complete Schools on sustainable construction and architecture!

On June 15th, Filipe Boni joined Programa 20 Minutos, a Brazilian podcast program hosted by journalist Breno Altman, for an hour-long conversation on urbanism, real estate speculation, and construction in Brazilian cities.

Boni addressed concrete mechanisms: why Brazilian cities grow the way they do, who pays the price when that growth goes unplanned, and where building performance fits into the equation.

One of the central topics was the transformation of housing into a financial product. Boni cited specific figures: in São Paulo, a family once needed 6 years of work to buy a 90m² apartment. Today, that same family needs 15 years to buy 45m².

This shift traces back to changes in Brazil's real estate fund regulations in 1977. From that point on, capital entered construction with a return-driven logic, making location a more important factor than building performance.

What residents actually experience inside the home, thermal comfort, acoustics, air quality, rarely enter the product equation.

The same logic explains the surge in micro-apartments. In São Paulo, units below a certain size made up 6% of new developments in 2006. By 2018, that share reached 62%. Today, it stands at 75%.

This isn't driven by demand for smaller spaces. It's investment logic: a compact unit fits a smaller mortgage payment and earns more on Airbnb.

Brazil has had a building performance standard since 2013, known as NBR 15575, covering thermal, acoustic, and structural requirements for housing.

Boni described what happens in practice: "It exists, but it isn't mandatory for licensing and is rarely inspected. An apartment can be legally delivered without the buyer having any real guarantee of performance."

He gave a concrete example: "A building might hit 60% thermal comfort hours over the year. That means 40% of the time, the resident is uncomfortable, too hot, or too cold. That 40% shows up in the energy bill, in air conditioning running all day, in blinds that stay closed."

He closed with the same logic applied to acoustics: "the standard sets a minimum sound attenuation between units, but pressure to cut construction costs pushes specifications right to that limit, or below it."

The conversation also covered urban sprawl: when cities grow driven by land speculation, they expand into areas that require entirely new infrastructure. Roads, power, water, transit. These costs are paid by the whole city, not just the developer who built far from the center.

Boni connected this directly to climate: "Every forced commute carries an emissions cost. A city that pushes housing away from jobs, retail, and services produces more transport emissions per resident, regardless of how efficient any individual building is."

Building energy use accounts for 37% of global carbon emissions. But if a resident has to take two buses to get to work and comes home to an apartment that overheats in summer, the environmental math doesn't close just by adding solar panels to the roof.

Watch the full episode on the link below!

Disclaimer: The video is in Brazilian Portuguese, but simultaneous translation and subtitles are available in multiple languages.

The world’s leading climate centers are converging on the same forecast: the El Niño currently forming has the potential to become the most intense in modern history.

Unlike previous events, this one is developing on a planet already 1.5°C above pre-industrial levels. For South America’s southern cone, the outlook includes rainfall significantly above historical averages, more intense storms, and stronger winds.

Most of the homes we live in were built for a climate that no longer exists.

Infrastructure that performs well under normal conditions, but fails precisely when it needs to work most.

Watch the full video on YouTube and learn which are the critical vulnerabilities of a residential building under extreme climate events, and what to do before the problem shows up!

Disclaimer: The video is in Brazilian Portuguese, but simultaneous translation and subtitles are available in multiple languages.