This research investigates the feasibility and potential of utilizing BFRP floors in modular buildings as a low environmental impact and cost-effective alternative to conventional floors. A modular building is introduced as a case study, the Natural Pavilion in Almere, to bring focus to the research and set a baseline for the requirements of the BFRP floor. A second case study, the bio-composite bridge in Ritsumasyl, is introduced to utilize its comprehensive dataset of material properties representing the state-of-the-art BFRP. Using the two case studies, two design solutions, a one-way and two-way floor, are developed. Comparing the designed BFRP floor to conventional floors such as cross-laminated timber, concrete hollow core slab, and concrete flat slab, several conclusions can be drawn: (1) The construction height of BFRP floors is similar to that of conventional floors. The weight of the floor is similar to a CLT floor, while a concrete floor is 6-8 times heavier. Design optimization is possible, and the amount of BFRP material utilized can be reduced by up to 21% for the one-way floor and 19% for the two-way floor. Additionally, the floor design proposed in this thesis is intended for buildings with a design life of 15 years and no specific fire resistance requirements. For structures with a design life of 50 years, it is imperative to increase the floor height to meet deflection criteria. Further research on fire resistance and additional measures is necessary to extend applicability beyond single-compartment buildings and terrace housing. (2) The environmental impact of a BFRP floor, assessed in terms of Global Warming Potential through a Life Cycle Analysis encompassing stages A1-A5, is found to be twice that of a concrete floor. Through optimization of the floor design and reduction of BFRP material usage, it is possible to achieve a reduction in CO2 emissions of approximately 10%. Nevertheless, in the current state-of-the-art, BFRP floors exhibit a higher environmental impact than conventional flooring systems. The use of resin and the production process are the primary contributors to CO2 emissions. The contribution from the production process requires nuance, as results heavily depend on the data source. Factors such as manufacturing techniques and production scale significantly affect this impact. By reducing the impact of the resin and production techniques while also exploring end-of-life possibilities for 100% bio-based BFRP, the environmental impact of BFRP floors holds potential for the future. (3) The floor cost is nearly twice as high as a comparable CLT floor. This can be attributed to introducing new design solutions with a sustainability focus, often resulting in increased costs due to lower demand, higher material and design expenses, and limited production scale. Even though current costs are much higher for BFRP floors than for conventional floors, there is potential for BFRP floors to become more cost-effective and competitive in the future, especially when the environmental impact is reduced. It is difficult to estimate how the price of BFRP floors would change over time, and therefore, it has not been taken into account in the results.