Climate-friendly building

Among other things, climate change is causing summer temperatures in cities to rise to unbearable levels. Intelligent construction methods, suitable materials, and urban planning measures can have a positive impact on the local climate, prevent heat accumulation, and cut CO2.

The rise in global average temperatures is leading to climatic changes worldwide. CO2 emissions from combustion engines are largely responsible for climate change.

Switzerland is particularly hard hit by climate change. Today, it is almost two degrees warmer here than in the period between 1850 and 19001, and the heat that keeps cities and conurbations in its grip during the summer months is already being felt. In the future, pessimistic forecasts indicate that summer temperatures could be up to 4.5 degrees higher than usual.

In global terms, temperatures have risen by 1.1 degrees Celsius compared with the pre-industrial era. For Reto Knutti, professor of climate physics at ETH Zurich, one thing is certain:

If humankind succeeds in stabilizing the global temperature increase at two degrees, we will be able to cope with the effects in technological and economic terms.

If this does not succeed and average temperatures rise by four or even five degrees, the world will look completely different in 100 years than it does today, the researcher warns.

Extreme weather events that occur more frequently and cause major damage to infrastructure and buildings herald the shift to the new warm period.

Recent examples are the heat waves in June and July 2019, and the dry summer of 2018 in Europe, which caused extensive damage to agriculture. Further consequences of global warming are the rise in sea level, flooding, and the scarcity of fresh water, known as water stress.

Last but not least, droughts and heatwaves increase the risk of forest fires. Like the boundaries between water and land, climatic zones are also undergoing long-term shifts. The temperate climate of Western Europe will not be left unscathed.

Learning from traditional building methods

The real estate sector is responsible for about one-third of the global energy demand and just over one-fifth of the greenhouse gases emitted worldwide2.

Urban planners and architects around the world are working on new, energy-saving construction methods and technologies that protect residents and buildings from extreme conditions. Several examples of this can be seen in the Middle East: While in Abu Dhabi glass skyscrapers rise into the sky like their counterparts in Western cities and devour vast amounts of energy for cooling, just 30 kilometers away, Masdar City, a model city for ecological construction, is currently being developed and will be self-sufficient with the help of solar and wind energy.

In reconstruction work in Aleppo in Syria, World Heritage Studies experts are primarily considering traditional building methods and materials, such as clay, which stores heat during the day and releases it again at night. The experts are also planning narrow alleys that are designed to provide shade on the one hand and a permanently cooling airflow on the other. Small windows ensure pleasant indoor temperatures and fountains in courtyards provide evaporative cooling. This traditional building knowledge has been handed down through the centuries and still proves its worth today as being climate-friendly.

Singapore's so-called Supertrees are part of the Gardens by the Bay sustainable urban development project. Reaching up to 16 floors high, these giant steel structures are covered with plants, and are also used to cultivate rare species.

Air circulation and green spaces

Can European cities benefit from the ideas implemented some 2,500 kilometers away? Like in desert regions, buildings in Central Europe have to withstand extreme temperature fluctuations between winter and summer. Rising temperatures and air pollution levels not only affect health, but also reduce productivity. Temperatures in Swiss cities during the summer are already up to ten degrees higher than in the surrounding area. Modern urban planning and sustainable construction can make a significant contribution to a pleasant local climate. The magic word here is densification. This is because every new building radiates heat and requires energy.

A compacted construction method can create more space for air circulation and can be used as green spaces or water areas. These in turn not only provide shade, but also have a cooling effect due to the resulting evaporation and remove pollutants from the air. Another advantage of green spaces is that, unlike sealed surfaces, they do not store heat and release it again at night, which prevents cities from cooling down. In metropolitan areas in particular, the vertical planting trend continues. Impressive examples include the "Bosco Verticale" in Milan, where around 900 trees grow on the balconies and façade, and the "Supertrees" in Singapore.

CO2-efficient buildings

In addition to the planting and air circulation concept, the buildings themselves are also able to positively influence the microclimate due to their huge energy-saving potential. Opting for suitable building materials improves the insulation of the houses and reduces heat transfer from the building envelopes. Clay, in particular, which is used in desert areas, is making a comeback in Europe too.

Similarly, the deliberate use of glass as a source of daylight and efficient technology and building automation help to minimize lighting, heating, and ventilation costs. Global Real Estate uses sustainable materials, green spaces and water areas, and climate-friendly systems such as solar panels and heat pumps.

Forward-looking investments

As a real estate owner, Global Real Estate pursues a sustainable approach to properties. Sustainable social, economic, and environmental considerations are incorporated into the relationships, business practices, and overall life cycle of real estate.

A discussion with Professor Reto Knutti

Reto Knutti, professor of climate physics at ETH Zurich, has been extensively involved in authoring the latest reports of the Intergovernmental Panel on Climate Change (IPCC). For him, the real estate industry has a key role to play in reducing global CO2 emissions.

Mr. Knutti, everyone is talking about climate issues. Why has it taken until now?

Humans bear most of the responsibility for the global rise in temperature. The Millennials are worried about their future and are mobilizing in great numbers. The implications of the topic directly affect them, giving the issue a social significance like never before. It is imperative that we reduce CO2 emissions.

How can this be achieved?

The greatest potential savings are in road traffic, which is responsible for around 30% of all CO2 emissions. At the same time, we need to invest heavily in renewable energies. There has to be an interaction between savings and the use of clean energies.

When it comes to real estate, it's easy to do something for the environment.

What could a world with reduced CO2-emissions look like?

One conceivable scenario is switching from transport to e-mobility and to synthetic fuels derived from the atmosphere for aircraft. Substituting fossil fuels in industry and agriculture is more difficult, but carbon sequestration is a possible option. CO2 is extracted from the atmosphere and stored underground. The technology has not yet been developed to handle large quantities and is too expensive. However, it could become increasingly important in the future.

What can the real estate industry do?

The real estate industry is responsible for one-fifth of global CO2 emissions. At the same time, real estate offers some easy ways to make an environmental contribution, such as insulation and heating systems.

Can investors influence climate development?

Of course. There have never been so many possibilities as there are today. Investors can use the various sustainability labels for orientation. The insight that sustainability pays off has become widely accepted today. Unfortunately, however, this is not yet the case in practice across the board.

Novum – the magazine