The energy topic is of paramount importance to the future environmental sustainability of our planet. In this context, buildings represent about 36% of greenhouse gas emissions, 40% of the final energy and about 60% of the electricity consumptions in the European Union and 28%, 30% and 55%, worldwide and respectively, thus playing a key role in the undergoing and future Energy Transition pathways.

In the EU, the global ambitious goals for 2030 and 2050 will have a great impact both in existing and new buildings, household and service types included. By 2030, greenhouse gas emissions will be reduced by at least 55%, together with a 42.5% renewable energy share and by 2050 Europe will be the first climate neutral continent. According to the IEA, near-zero or even positive energy construction and deep energy renovations can reduce the sector’s energy use worldwide by 30% in 2050, even with doubling of the global floor area.

This talk will give an insight into the likely evolution of the building sector up to 2050, in terms of energy conversion and usage. Although with uncertainties about which multiple technologies will be the most cost-effective and successful, the main roadmap is already defined with a predicted sector electrification of up to more than 70% of the final energy consumption, the expected phase-out of fossil fuels boilers, complemented with increasing relevance of heat pumps, intelligent ventilation systems, solar photovoltaics and energy storage, both thermal and electric. Hydrogen is unlikely to play an important role in direct heating, but might be an important local energy carrier by reversible conversion from and to electricity through electrolysis with gas storage plus fuel-cell or cogeneration. Also, as concerns with human comfort and long-term health issues increase, most solid fuels should be banned for heating and cooking and the building energy simulation software will have to include detailed inside air quality and human comfort analyses. The software will be used, not only at design stage, but also as part of a monitoring and energy management operational package, to allow the fully integration of smart technologies.

With all these goals, technical changes and incentives, challenging times are ahead for the building sector!

Keywords: Energy efficiency, building sector, ZEB, renewable energies, energy storage, sustainability, human health/comfort, IAQ – Inside Air Quality, Energy Conversion and Management, Building Energy Modelling.