## 4 Discussion  
The results validate the model's effectiveness for its intended purpose: creating a national-scale representation of building energy performance to inform data-driven decarbonization policies. The model estimates NRPEC and GHG emissions for over 1,246,000 buildings across Spain, enabling a comprehensive analysis of the residential building stock. Its high reliability in aggregating building data supports decarbonization strategy development and impact assessment at multiple levels--district, neighborhood, city, region, and national--and across building typologies within urban or regional areas. Additionally, the model identifies characteristics and locations of the lowest-performing building typologies.  
While the model lacks precision at the individual building scale due to limited energy system data and the influence of unidentifiable outliers, this limitation does not detract from its purpose. Its design centers on large-scale analysis rather than single-building specificity, making it well suited for informing broad decarbonization strategies.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Building Type** & **Number of Buildings** & **Built Surface** & **Average NRPEC** & **Total NRPEC** & **Average GHG** & **Total GHG** \\  & **Buildings** & **Area** & **kWh/m\({}^{2}\)y** & **kWh/y** & **kgCO\({}_{2}\)/m\({}^{2}\)y** & **kgCO\({}_{2}\)/y** \\ \hline SFH \(<\) 1940 & 2,134,183 & 301,957,824 & 266.36 & 76,066,608,803 & 57.95 & 16,697,047,758 \\ SFH 1941-60 & 933,516 & 127,930,130 & 268.90 & 32,719,342,689 & 58.56 & 7,146,662,044 \\ SFH 1961-80 & 1,461,467 & 212,817,509 & 262.20 & 53,086,111,371 & 57.20 & 11,642,788,779 \\ SFH 1981-07 & 2,464,120 & 387,925,847 & 224.34 & 82,938,611,561 & 49.22 & 18,338,783,131 \\ SFH 2008-11 & 222,509 & 39,467,375 & 171.80 & 3,641,922,091 & 37.49 & 1,394,566,222 \\ SFH 2012-23 & 195,711 & 38,363,725 & 111.66 & 3,8317,920,395 & 23.64 & 808,278,271 \\ MFH-A \(<\) 1940 & 91,408 & 26,152,128 & 237.64 & 5,979,520,959 & 51.42 & 1,291,723,803 \\ MFH-A 1941-60 & 71,817 & 20,638,135 & 238.01 & 4,836,948,841 & 51.16 & 1,037,677,545 \\ MFH-A 1961-80 & 149,544 & 54,103,556 & 224.35 & 11,890,514,820 & 48.19 & 2,543,450,158 \\ MFH-A 1981-07 & 251,349 & 208,592,917 & 196.73 & 39,098,724,933 & 42.04 & 8,288,545,922 \\ MFH-A 2008-11 & 28,532 & 32,523,999 & 162.83 & 5,110,705,256 & 34.34 & 1,067,181,849 \\ MFH-A 2012-23 & 11,379 & 14,596,361 & 99.93 & 1,276,785,871 & 20.91 & 260,238,373 \\ MFH-B \(<\) 1940 & 48,503 & 40,228,068 & 221.33 & 8,636,836,437 & 46.74 & 1,823,774,145 \\ MFH-B 1941-60 & 57,417 & 60,688,978 & 234.77 & 13,757,176,878 & 49.32 & 2,896,350,094 \\ MFH-B 1961-80 & 277,315 & 455,999,315 & 214.47 & 93,474,623,910 & 45.03 & 19,700,388,275 \\ MFH-B 1981-07 & 239,096 & 537,966,687 & 188.02 & 96,025,887,566 & 39.34 & 20,027,333,473 \\ MFH-B 2008-11 & 28,888 & 74,935,487 & 153.71 & 10,862,847,649 & 31.65 & 2,232,384,138 \\ MFH-B 2012-23 & 12,358 & 45,046,627 & 94.11 & 3,839,665,175 & 18.94 & 764,431,671 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Number of buildings, built surface area, average GHG emissions kgCO\({}_{2}\)/(m\({}^{2}\)y) and total GHG emissions kgCO\({}_{2}\)/y per residential building type in the Spanish LTRS (ERESEE). SFH: single-family house, MFH-A: multi-family house with 3 or fewer floors, MFH-B: multi-family house with more than 3 floors.