Modern wall systems are constructed by overlayering toxic, petrochemical materials. Hempcrete can replace this complex stack as a monolithic wall that serves structure, insulation, moisture buffering, acoustic damping and fire resistance in one single material. Hemp shiv and a lime binder form a self-supporting mass whose performance depends parameters like density, compaction methods, binder-to-hemp ratio and shiv orientation. Under a 75% end-of-life recycling scenario, hempcrete removes a net 14 kg CO2-equivalent per functional unit from the atmosphere, making it a carbon-negative building material. Field observation on a full-scale hempcrete wall show that the manufacturing workflow is still artisanal, subjective and weather-dependent, leading to high labour demands and unreliable wall performance.

This research aims to produce a self-standing and insulating hempcrete wall with predictable performance. An experiment is set up, varying manufacturing parameters: layer height, compaction factor, orientation and binder type. Layers thinner than 10cm and compaction above 50% prevented interlayer density gradients, preserving hygrothermal properties and providing a safe mechanical margin. Top-down compaction increased compressive strength exponentially, but showed big settlement. Monolithic hempcrete still needs extra stability. Strategies proposed in this research include altering mix design, section geometry or integrating natural reinforcements. However, life-cycle recalculations show a carbon-neutral ceiling: further increasing density, binder ratio or wall thickness should be done with care, to keep the overall emissions net-negative.