# Are Green Buildings an Indicator of Sustainable Development?
## 4 Conclusions  
This study intended to establish whether a direct link between green buildings (GBRS) and sustainable development (GDP and GHG) can be determined. Considering data from the Eurostat Database for the 27 EU countries in the 10-year-period between 2010 and 2019, the spread of green buildings is estimated through the adoption of GBRS certifications (LEED, BREEAM, DGNB and HQE) taken from the public  
Figure 12: Relationship between GBRS and GHG emissions from buildings in the EU (2010–2019). Figure 13: Relationship between GBRS and GHG emissions from buildings in the EU (2010–2013 and 2015–2019). directories. This indicator is compared to GDP and GHG emissions as measures of sustainable development. GDP and GHG emissions are also correlated to renewable energy consumption and climate conditions to prove the assumptions of the EKC curve that, in a developed region such as the EU-27, it assumes a growing economy (more GDP) along with an environmental improvement (fewer GHG emissions). The relationship between the indicators is examined through a simple linear regression to determine the equation representing the line that better fits the data of a dependent variable as a function of an independent variable. The results confirm the hypothesis of the EKC curve and the outcomes of another study [7], showing that a higher income per capita is related to fewer GHG emissions per capita due to the best technologies already in place. The outcomes are different from a second study [8] that assessed data in a mutating period within the EU (1995-2010). The correlations are consistent, especially if 2014 is excluded from the 10-year period since it was characterised by extreme climate conditions with significantly fewer heating degree days compared to other years, affecting the trend of the linear regressions. Moreover, global warming is decreasing the energy demand in the heating-dominated zones but is increasing way more electricity demand in the cooling-dominated zones, causing higher GHG emissions [38; 39]. The results finally show that the adoption of GBRS can be used as an indicator of sustainable development within the EU-27. More green buildings certifications (dependent variable) are related to both:  
* Higher GDP per capita (independent variable), with a linear equation \(\mathrm{y}=0.0016\mathrm{x}+24.286\), \(p\)-value = 0.0004 and \(\mathrm{R}^{2}=0.8475\). * Fewer GHG emissions (independent variable), with a linear equation \(\mathrm{y}=-0.1391\mathrm{x}+1819.6\), \(p\)-value = 0.0002 and \(\mathrm{R}^{2}=0.8825\). The regressions are characterised by a consistent statistical significance since the \(p\)-value is lower than the conventional threshold of 0.05 (i.e., probability > 95%): the variance of GBRS certifications expresses a consistent probability of the variance of GDP per capita and GHG emissions. This is mainly due to the extra upfront cost needed to implement advanced construction technologies that, in the end, cut GHG emissions during the building lifecycle. This is confirmed by the fact that, at the end of 2019, within the EU, the majority of the GBRS certifications were in France (4465), Germany (1902), The Netherlands (905), Spain (812) and Sweden (783) [17; 18; 19; 20]. These countries are characterised by both a prosperous GDP and a decreasing GHG, thanks to a consistent share of renewable energy sources [40; 41; 42; 43]. On the contrary, at the end of 2019, countries with less GBRS were Cyprus (0), Slovenia (1), Malta (3) Croatia (3), Latvia (16), Estonia (23) and Greece (30). These countries are in a previous phase of the EKC curve, with less GDP and less adoption of renewable energy sources [44; 45; 46; 47; 48; 49; 50]. The findings demonstrate that the amount of GBRS that will populate the EU in the next years can be estimated by knowing the trend of the GDP and the GHG emissions.