High thermal resistance and low-carbon emission façade technologies for sustainable construction

Given that the building sector currently accounts for up to 40% of global energy consumption, the development of low-carbon and high-thermal-resistance facade technologies has become imperative in line with the Sustainable Development Goals (SDGs). This thesis addresses sustainable building envelope solutions through a multi-dimensional approach, based on six original studies evaluated from various perspectives. In the first part of the thesis, the performance of building envelopes enhanced with thermal super-insulation technologies, vacuum insulation panels (VIPs) and aerogel blankets, has been assessed. Both materials demonstrate significantly higher thermal resistance compared to conventional insulation solutions due to their exceptionally low thermal conductivity values (0.005-0.008 W/mK for VIPs and 0.013-0.018 W/mK for aerogels). However, key challenges in field applications, including thermal discontinuities (hot-cold spots), thermal bridging, installation precision, and cost, must be carefully addressed to ensure sustainable implementation. Field performance analyses within the scope of the thesis indicate that effective integration of these technologies can reduce building energy losses by 37% to 64%. In the second phase, the role of Building Information Modelling (BIM) processes in enhancing the energy efficiency of existing buildings has been investigated. Findings reveal that BIM-based digital twins can accurately predict energy consumption scenarios and offer energy efficiency potential in the range of 15% to 22%. Furthermore, BIM significantly contributes to the modelling, simulation, and optimisation of innovative facade solutions. The third study explores the thermal performance improvements achieved by applying an innovative insulation plaster (IIP) onto a conventional briquette. It was observed that the U-value of traditional briquettes, initially measured at 5.5 W/m2K, decreased to 2.86 W/m2K with the use of a 20-20 thickness configuration of IIP, indicating a 47.9% improvement. The fourth study experimentally evaluates the performance of this insulation plaster under fire conditions. Coarse and IIP layers applied in different thicknesses were exposed to temperatures between 300°C and 600°C for durations of 60-120 minutes in furnace conditions. Additionally, uncoated reference specimens were evaluated for comparison, allowing an assessment of the fire resistance of coated versus uncoated building elements. The results demonstrated that the IIP with a thickness of 30 mm could maintain compressive strength above 30 MPa even after 120 minutes at 600°C. CFD and regression modelling suggested that this plaster could withstand up to 600°C for 173 minutes and reach maximum exposure temperatures of up to 861°C within 120 minutes. Finally, the sixth study assessed the thermal performance of briquettes incorporating bamboo fibre using the coheating test method. Specimens prepared with 2%, 4%, and 6% bamboo content showed U-values of 4.698, 3.94, and 2.77 W/m2K, respectively. The sample with 6% bamboo demonstrated an approximate 49.9% improvement in thermal transmittance compared to conventional briquettes. Whilst this indicates a thermal performance level comparable to IIP, it offers less fire protection, thereby warranting composite solutions. In conclusion, this thesis presents an integrated approach that transcends conventional insulation strategies by bringing together material engineering, energy systems, and digital building design. From IIP to natural-fibre briquettes, from super-insulation materials to digital modelling, all components reveal how the sustainable building envelope can be enhanced not only in terms of energy efficiency, but also regarding safety, environmental impact, and economic feasibility.