A retrofitting framework for improving curtain wall performance by the integration of adaptive technologies

Energy efficiency and the reduction of carbon emissions have become the main climate goals for newly constructed or existing buildings. In the building sector, curtain walls (CWs) account for the majority of unwanted solar heat gain and consume most of the energy used. In this context, adaptive technologies (ATs) offer a wide range of alternative solutions to improve the performance of CWs. This study aims at developing a comprehensive framework for retrofitting CWs through the integration of ATs. Based on a comprehensive analysis of previous literature, the proposed three-stage framework provides a guide for enhancing the performance of CWs by evaluating and comparing retrofitting scenarios using ATs. The three stages include pre-retrofit survey, retrofit process, and monitoring process. To achieve this goal, curtain wall systems, retrofitting levels, and sub-practices are discussed. The integration ability of ATs into CW systems is assessed according to functional, structural, and technical properties. Integration scenarios are evaluated based on SWOT analysis, performance criteria, adaptive parameters, and retrofitting practices to assess their efficiency. Results show that integration scenarios of materials like electrochromic and semi-transparent photovoltaic glazing are applicable to all CW systems with remarkable performance enhancement. Phase change materials and liquid infill tunable glazing are the least applicable materials. Integration scenarios of adaptive systems involving green walls and dynamic shading devices provide the greatest functional benefits. Whereas, algae facades should only be installed in newly constructed buildings. In conclusion, the study proves that the integration of ATs into CWs offers promising potential for improving CW performance.