Spatial and environmental requirements for integrating decentralised wet anaerobic digestion systems in heritage urban contexts: George Town, Penang

Integrating decentralised food waste-to-energy (FWtE) systems within heritage urban environments demands alignment between technical infrastructure, spatial feasibility, and conservation responsibility. While decentralised wet anaerobic digestion (AD) systems have been extensively studied from engineering and environmental perspectives, limited research has translated their operational parameters into architectural integration frameworks for heritage adaptive reuse contexts. This study examines the spatial and environmental requirements for integrating decentralised wet AD systems within heritage urban settings, with reference to George Town, Penang. An analytical literature review was conducted to extract and categorise operational and biochemical parameters of wet AD systems, identifying their structural and environmental implications. This was followed by a comparative precedent analysis of three decentralised installations to evaluate spatial configuration, structural loading, and environmental control conditions. Through process-to-space mapping and cross-case synthesis, technical process requirements were translated into architectural integration criteria. The findings reveal consistent functional compartmentalisation across feedstock preparation, digestion, gas handling, energy conversion, and digestate management zones, each imposing specific structural, ventilation, safety, and service access requirements. The study proposes a structured set of spatial and environmental criteria that convert technical process demands into architectural considerations, enabling informed early-stage feasibility evaluation of decentralised wet AD integration within conservation-sensitive urban contexts.