Sensitivity Analysis

The results from the sensitivity analysis into impacts on emissions and energy use from reduced/increased construction demand (denoted as low/high) are shown in Figure 9. The percentage values indicate the reduction from the reference level (cf. the pathway reduction results in Figures 7 and 8).

**Figure 9.** Sensitivity analysis based on reduced or increased construction demand for the different pathways with (**<sup>a</sup>**,**b**) depicting the impact on total energy demand, and (**<sup>c</sup>**,**d**) depicting the impact on emissions, for low and high construction demand, respectively.

The sensitivity analysis demonstrates that grea<sup>t</sup> variances are found in between scenarios of reduced or increased construction demand regarding total energy use. The main implications are seen with regards to an increased construction demand potentially leading to the energy demand remaining relatively stagnant (Pathway 2 and 3) or even growing by 13% to 2030 as in the biofuel+CCS pathway.

In this case, the biofuel demand increases to 11 TWh in 2030 and to 15 TWh in 2045 (compared to 4 TWh in 2015). For the electrification pathway, the electricity demand increases to 13 TWh in 2030 and 21 TWh in 2045 (compared to 8 TWh in 2015). In contrast, reduced construction demand combined with material efficiency measures could reduce to total energy demand by 41–56% implying a total energy demand of between 14–18 TWh in 2045.

Regarding emissions, the sensitivity analysis demonstrates that even with an increased construction demand, it will be possible to reduce CO2 emissions by at least 85% to 2045 compared to 2020 with the combination of measures proposed in this roadmap. However, it also demonstrates that the emissions reduction in the short and medium terms could be slowed down further and possibly impact the potential to reach the sector goal of 50% emissions reduction to 2030 [49]. On the other hand, a slowdown in construction rates could make emissions reductions of over 60% to 2030 possible.
