A Multimodal AI Framework for Sustainable Inventory Management and Waste Reduction in the uPVC Fenestration Industry

The construction industry faces critical challenges related to resource inefficiency and waste generation, particularly in offsite manufacturing processes, which are increasingly recognised as key to improving productivity and sustainability. Recent advancements in multimodal artificial intelligence (AI) offer promising solutions to these issues by enabling more efficient resource utilisation and waste reduction. Building on this progress, this work proposes a smart multimodal AI framework to optimise inventory management and minimise material waste in uPVC window and door fabrication. The framework integrated heterogeneous data streams, including batch production time-series data, LiDAR-derived spatial scans, and high-resolution imagery, to provide a comprehensive understanding of raw material utilisation throughout the production lifecycle. At its core, a custom Variational Autoencoder (VAE) fused detailed tabular process data, such as input lengths, offcut generation, and waste percentages, with visual features extracted via a ResNet-50 pretrained model. This fusion generated a unified latent representation that effectively captured material and geometric properties. Hierarchical clustering within this latent space revealed material usage patterns, enabling the development of optimised inventory strategies and storage layouts that enhanced retrieval efficiency and operational safety. Preliminary experimental results demonstrated the frameworks ability to identify recurring offcuts suitable for reuse and achieved substantial reductions in uPVC material waste. These findings align with sustainability and net-zero objectives, showcasing the potential for significant resource efficiency and cost savings. The study introduces a scalable, data-driven AI approach for digitised inventory management in offsite construction, demonstrating its potential for sustainable building and infrastructure development through actionable insights and practical solutions.