According to Bloomberg, the buildings and constructions around us could hold the key to meeting global commitments on climate change. Today on Sonneil’s blog we discuss this article and reflect on the current situation in Spain.

“As the Covid-19 pandemic forces us to rethink how we use the spaces in which we live and work, an ever-increasing number of countries and companies are committing to a net zero approach that will create a more sustainable world.” This is the beginning of Bloomberg’s article.

Let’s start at the beginning, what is a net zero building?

Net zero: the green target

According to the World Green Building Council (WorldGBC), buildings and the construction industry are responsible for around 30% of global energy consumption, 30% of greenhouse gas emissions and 50% of CO2 emissions in large cities.

In view of this reality, reaching net zero is one of the medium and long term objectives of the construction industry. Basically, it is a certification that ensures that the building has a very high energy performance, with net zero energy use (net zero energy consumption) or zero carbon emissions.

The WorldGBC sets a very ambitious goal in this regard: starting in 2030, all newly constructed buildings must operate with zero carbon emissions. And, by 2050, 100% of buildings must operate on a zero carbon basis.

Why pursue a net zero strategy?

It seems pretty obvious, right? According to Bloomberg, CO2 pollution continues to increase every year (a new record was set in 2019, with a total of 36.81 billion metric tons of emissions).

So the concept of net zero is emerging as one of the pillars of the fight against climate change, and the construction industry is turning into an ally. In addition, the number of buildings is expected to double in the next 30 years.

According to the Global Report on Buildings and Construction published by the Global Alliance for Building and Construction during the COP25 in Madrid, to achieve the commitments of the Paris Agreement and the United Nations’ Sustainable Development Goals, it is essential to decarbonise the housing and construction sector.

Energy efficiency measures could generate a 48% reduction in global emissions by 2030.

 How to achieve a net zero goal?

Renewable energies play a fundamental role in sustainable architecture. Without them, reaching net zero emissions is indeed a utopia. Learn these names well (if you do not know them already):

  • Solar Thermal Energy. Installation of solar panels that generates thermal energy to, for example, supply hot water to homes.
  • Photovoltaic Solar Energy. This system also uses solar panels but, in this case, they produce electricity that can replace the conventional electricity grid.
  • Biomass. Have you heard of domestic pellet boilers? This is the modern (and most widely used) version of a traditional fireplace. The idea is to make use of agro-industrial waste, organic animal matter (compost) or vegetable matter (pruning waste) to obtain hot water and heating for homes. In addition, if thermal power stations are installed, electricity can also be generated.
  • Mini Wind Energy. Ideal for windy areas. Small wind turbines can be installed in homes to generate electricity.
Sustainable net zero buildings

And what happens in Spain?

On September 24, 2020, the new Technical Building Code (CTE) came into force, which is in line with the global objectives of reducing emissions, saving energy and promoting renewable energy. According to, this modification is intended to improve energy efficiency in Spain’s residential areas by reducing the use of non-renewable energy sources such as oil, coal and gas.

The two most important changes that have been applied to the CTE are the following:

  • Total energy consumption limit. Buildings already constructed will be allowed 40% more total energy consumption than new constructions.
  • Control of demand. The list of requirements to determine whether a building complies with energy consumption limits varies, depending on the area, geometry, qualities, orientation, ventilation, humidity…

In addition, energy rehabilitation of buildings is considered a possible engine for generating employment and wealth after the Covid-19 crisis. In this regard, it is worth noting that the Long-term Strategy for Energy Renovation in the Building Sector in Spain, published by the Ministry of Transport, Mobility and Urban Agenda, was given an outstanding rating by the group of experts at the Buildings Performance Institute Europe, which considers the Spanish plan to be the best in the European Union.

Fun fact: on the website of El Confidencial you can see some of the most sustainable buildings in Spain.

Sustainable buildings will contribute to protecting and maintaining our environment, helping us to take care of paradises such as those found on the Spanish coasts.