## 4 Results and Discussion  
### Energy Use Intensity (EUI) Performance of Fibre-Reinforced Leca-Lwac  
The EUI and energy savings at 0\({}^{\circ}\), 45\({}^{\circ}\) and 90\({}^{\circ}\) building orientation in four cities of diverse climatic zones are shown in Table 5. The table shows a comparison of the energy performance of the integral structural-insulation fibre-reinforced LECA-LWAC (without insulation) against traditional construction materials, including NWC, sand-cement and clay bricks. [PERSON] et al. [53] analysed the data provided by the New Buildings Institute and determined that the average certified annual EUI for residential buildings was 220 kW\(\cdot\)h-m\({}^{-2}\) in the USA. A Malaysia Green Building Index (GBI)-certified green office building in Kuala Lumpur was designed at an annual EUI of less than 150 kW\(\cdot\)h-m\({}^{-2}\)[54]. [PERSON], et al. [55] investigated Leadership in Energy and Environmental Design (LEED)-certified residential high-rise building average annual EUI values in the USA for different climatic zones and they were as follows:  
1. Warm and Hot (ASHRAE 1-3) = 140 kW\(\cdot\)h-m\({}^{-2}\)
2. Mixed (ASHRAE 4) = 159 kW\(\cdot\)h-m\({}^{-2}\)
3. Cool (ASHRAE 5) = 150 kW\(\cdot\)h-m\({}^{-2}\)
4. Cold (ASHRAE 6-7) = 173 kW\(\cdot\)h-m\({}^{-2}\)  
The EUI requirement for Putrajaya was based on the Malaysia GBI-certified building and the rest of the cities were based on the climatic zone suggested above. The worst-case scenario of the EUI at 90\({}^{\circ}\) orientation was used to evaluate against the approved EUI values of the certified GBI and LEED buildings. Putrajaya annual EUI values at 90\({}^{\circ}\) orientation for fibre-reinforced LWAC ranging from 147.0-149.6 kW\(\cdot\)h-m\({}^{-2}\) qualify for the GBI requirement of less than 150 kW\(\cdot\)h-m\({}^{-2}\) while traditional materials failed to qualify. The best performance EUI was HST0.75 + PP0.1 hybrid (147.0 kW\(\cdot\)h-m\({}^{-2}\)) and HST0.75 + PP0.3 hybrid (147.0 kW\(\cdot\)h-m\({}^{-2}\)). Istanbul annual EUI values at 90\({}^{\circ}\) orientation for fibre-reinforced LWAC ranging from 146.7-149.8 kW\(\cdot\)h-m\({}^{-2}\) qualify for the LEED requirement in a cool climatic zone of less than 150 kW\(\cdot\)h-m\({}^{-2}\) while the traditional materials failed to qualify. The best performance EUI was HST0.75 + PP0.3 hybrid (146.7 kW\(\cdot\)h-m\({}^{-2}\)) and PP0.3 (146.7 kW\(\cdot\)h-m\({}^{-2}\)). Makkah annual EUI values at 90\({}^{\circ}\) orientation for fibre-reinforced LWAC ranging from 159.2-165.0 kW\(\cdot\)h-m\({}^{-2}\) failed to qualify for the LEED requirement in a hot climatic zone of less  
Figure 5: Building Orientation: (**a**) Case 1 Base Model—Building front facing North (0\({}^{\circ}\) Orientation); (**b**) Case 2 Building front facing East (90\({}^{\circ}\) Orientation). than 140 kW\(\cdot\)h\(\cdot\)m\({}^{-2}\). The best performance EUI was HST0.75 + PP0.3 hybrid (159.2 kW\(\cdot\)h\(\cdot\)m\({}^{-2}\)) and HST0.75 + PP0.1 (159.2 v). Based on the IEA (2017) energy data, the EUI estimate for residential buildings of Saudi Arabia was 195.8 kW\(\cdot\)h\(\cdot\)m\({}^{-2}\)[56] and the Eastern Province with Zone 1 climate was similar to Makkah for apartments that have a EUI of 196.5 kW\(\cdot\)h\(\cdot\)m\({}^{-2}\)[57]. EUI performance of the fibre-reinforced LWAC was much lower than the above EUI estimates. Lillhardal annual EUI values at 90\({}^{\circ}\) orientation for fibre-reinforced LWAC ranging from 201.0-212.7 kW\(\cdot\)h\(\cdot\)m\({}^{-2}\) failed to qualify for the LEED requirement in a cold climatic zone of less than 173 kW\(\cdot\)h\(\cdot\)m\({}^{-2}\). The best performance EUI was PP0.3 (201.0 kW\(\cdot\)h\(\cdot\)m\({}^{-2}\)) followed closely by the HST0.75 + PP0.3 hybrid (203.7 kW\(\cdot\)h\(\cdot\)m\({}^{-2}\)). The EUI values of Putrajaya and Istanbul for monolithic structural-insulation fibre-reinforced LWAC (without additional insulation) qualified for the certified building EUI requirement of less than 150 kW\(\cdot\)h\(\cdot\)m\({}^{-2}\) for GBI and LEED.