Integrated performance evaluation of glazing and rooftop PV systems using VIKOR-MCDM and building simulation

Integrating natural daylight and renewable energy systems at the early design stage is vital for improving energy efficiency and economic sustainability in commercial buildings, especially in hot and humid climates like Surat, India. This study presents a simulation-based framework that combines energy and daylighting analysis in DesignBuilder with the VIKOR multi-criteria decision-making (MCDM) method to evaluate twelve glazing alternatives (A1–A12) across three window-to-wall ratios (20%, 40%, 60%) for a commercial restaurant building in Surat, India. Performance indicators—including Net Present Value (NPV), Internal Rate of Return (IRR), Useful Daylight Illuminance (UDI), Daylight Factor (DF), Daylight Harvesting (DH), and Predicted Mean Vote (PMV)—were used to determine optimal configurations. Clear Cosmos (A2) and Platinum (A3) emerged as top-performing glazing options due to their moderate-to-low Solar Heat Gain Coefficient (0.29 and 0.14) and low U-values (3.8 and 3.6 W/m 2 K), which minimized heat gain, improved thermal and visual comfort, and reduced cooling loads. Economically, A2 achieved the highest IRR, while A3 maximized NPV. The study also assessed three monocrystalline PV technologies—Mono-PERC Mono-facial, Mono-PERC Bi-facial, and TopCon Bi-facial—across rooftop coverages of 63%, 80%, and 100%. Mono-PERC Mono-facial panels at 63% coverage offered the best cost-performance ratio, generating 64,976 kWh annually with a 27.44% ROI and a 3.64-year payback. Although high-capacity systems provided greater long-term energy output, their higher initial costs resulted in extended payback durations. EPI-based benchmarking confirmed the accuracy of simulated outputs, with values between 54.1–67.3 kWh/m 2 /year (depending on glazing and WWR), aligning well with ECBC 2017 benchmarks. These findings underscore the importance of integrated simulation and MCDM approaches for selecting energy-efficient, economically viable glazing and PV systems to support climate-responsive commercial building design. • Developed a simulation-integrated VIKOR-MCDM framework for early-stage building design analysis. • Coupled energy and daylight simulations from DesignBuilder with multi-criteria decision methods. • Assessed glazing and PV alternatives across design scenarios and hot-humid climate conditions. • Enabled data-driven, climate-responsive, and cost-effective design decisions from the outset.