Timber–concrete composite floors are currently used as sustainable flooring solutions. To broaden their application, improvements in construction efficiency are required. The hybrid system herein proposed combining timber, steel, and concrete members eases on-site assembly and can be partially prefabricated in factory. Timber beams and steel members, connected with interposed wooden planks through mechanical fasteners, create an oak-beamed ceiling supported by timber–steel composite beams. The steel element, with height equal to the insulating layer already required for energy and comfort purposes, plays a key role during concrete casting, allowing timber-steel composite beams to support fresh concrete and workmen loads with limited deflection. This composite action reduces the timber beam depth, thus lowering material use, and eliminates temporary supports, simplifying construction and reducing costs. These advantages promote wider adoption of timber floors, valued for both sustainability and aesthetics. After concrete hardening, a three-member hybrid floor is obtained. Neither numerical evaluations nor specific experimental tests are required because, even disregarding the steel contribution, the system’s performance, simply evaluated with the rules of the Annex B of Eurocode 5, generally accepted also for timber–concrete composites, matches that of conventional solutions with deeper timber beams. The proposed hybrid floor thus combines sustainability, prefabrication, construction efficiency, and compatibility with existing design standards.

hybrid timber floors, timber-steel composite beams, self-bearing floor, Eurocode 5 design, sustainable flooring system, prefabrication, thermal insulation