The European Union (EU) aims to establish a guideline that requires all new buildings to comply with nearly zero-energy buildings (NZEB) by 2030. This decision involves new technologies based on concepts that meet international standards. This research aims to review the literature on 'net zero-energy building' and analyses the possibility of applying this research on nine statistically representative neighbourhoods of the building stock'in Belgium, depending on the built density. All the areas, grouped into four categories (urban, peri-urban, suburban, and rural neighbourhoods), were used for current energy consumption analysis and to evaluate prospective scenarios based on four major challenges, namely climate change, building renovations, photovoltaic panels, and sustainable mobility. In addition, a new approach combining several scenarios to further improve energy needs at the neighbourhood scale is also highlighted. The nine different types of neighbourhoods studied are commonly found in different countries across the EU. The average reduction in energy consumption of neighbourhoods (buildings + daily mobility) in 2040 (compared to reference year 2012) will likely reach 5.69% attributable to a 20% reduction in distances travelled, 6.48% to climate change, 12.95% to the current annual buildings renovation rate, 18.76%-100% electric cars, 22.26% for doubling the current buildings renovation rate, 31.62% and 63.25% to a light or heavy renovation of the entire building stock, respectively. Moreover, installing 20 m 2 of solar panels on the rooftops of each residential building would produce renewable energy equivalent to 6.53% of the current global energy consumption. Finally, the results show that more than 90% of current energy consumption can be reduced at the neighbourhood scale (buildings + daily mobility) by combining a heavy renovation of all the buildings, electric vehicles, and photovoltaic panels. This scenario allows reaching the 'nearly zero-energy' target at the neighbourhood scale.

Energy consumption in buildings results in CO2 emissions and it is necessary to reduce energy consumption thus its related emissions. This research is included in the Wal-e-cities project, which is funded by the European Regional Development Fund (ERDF) and aims to create tools that facilitate the transition toward smart territory. The annual heat consumption (HC) and heat demand (HD) of Wallonia building stock of more than 1,700,000 buildings are assessed. Subsequently, the developed energy models are coupled with a geographic information system (GIS) to calculate and map the HC and HD. The HC and HD are calculated for each building and are represented by different levels of territorial aggregation, namely neighbourhood, municipality, and urban region scales. The highest HC values were observed in large cities and main industrial areas, whereas the lowest values were observed in rural areas. For residential sector, HC is mainly related to the number of dwellings, which differs from that of tertiary and industrial sectors where HC also depends on the nature and function of buildings. Based on mean values at the neighbourhood scale, the HD is 16.44% lower than the HC for the residential sector, 15.78% lower than the HC for the tertiary sector, and 9.26% lower than the HC for the industrial sector. The proposed energy models are validated. The relative differences between annual HC calculated in this study and that provided in the regional energy reports are -5.82% for the residential sector, -14.29% for the tertiary sector, and -2.02% for the industrial sector.

No abstract

No abstract

No abstract