The characterization of limecrete slabs made of plant extract and hemp fibers of an old monument, Bichili haveli, located in Udaipur, Rajasthan, India was carried out to understand the traditional materials used and its production. Limecrete of ratio 1: 1: 3 (Lime: brickbats: sand) were produced with hemp fibers to acts as flexural members. The hardened limecrete shows the predominate phases of calcium carbonate such as calcite with other polymorphs (vaterite & aragonite), tobermorite and Calcium alumina-silica hydrates (CASH). The organic analysis has confirmed the presence of biomolecules which are originated by the addition of fermented plant extracts that acts as a natural admixture during the preparation of limecrete slabs. With the help of organic additives, limecrete also acts as a Carbon Capture and Utilization (CCU) unit and sequester 15–20% of atmospheric carbon di oxide (CO₂). The current study reclaims the lost old technology which uses low energy-intensive materials like lime, brick powder & bats, plants extracts and hemp fibers at the same time 20% lesser cost than cement concrete. The experimental evidence from the present research proves that the limecrete slabs have enough strength and durability, also acts as CO₂ capture materials in mitigating global emissions. Limecrete can be used for the restoration of the heritage building as well as in modern construction for low rise buildings.