The lighting industry is facing a big challenge regarding the design of more sustainable lighting products. Although the development of LED technology has contributed enormously to their energy efficiency, more efforts are needed in reducing not only the energy consumption but also the use of key materials present in electronic components for a sustainable design. This can be achieved through new modular and configurable designs that can replace the generic LED luminaires that are disposable with a customized, sustainable product with high functional value, which should be supported by an assessment along its entire lifecycle to know the environmental performance to support the designs.This study conducts life cycle assessment models to quantitatively assist sustainable design decision-making of a novel LED modular luminaire's architecture. Firstly, a comparative LCA between a new luminaire and an existing product was performed to be used in an industrial environment. The results from this study showed a reduction of around 30% in the environmental impact categories that are more influenced by the energy consumption in the use stage (such as climate change and primary energy demand), whereas the resource depletion impact category associated with the elements was reduced by around 50%. The latter is mainly attributed to the reduction in the total circuit board area for the LED modules and the use of LEDs with less environmental burden made possible by eliminating the major contribution from the gold bond wire.Secondly, several scenarios are proposed based on modularity and replacement to change the LED luminaire life cycle towards more sustainability in the energy and material impact context. A scenario dedicated to analysing the optimal LED luminaire usage times in terms of energy and material efficiency is included. Two further scenario calculations treat the topic of replaceable components. One scenario investigates if exchanging the LED module regularly brings benefits by decreasing the primary energy demand category. The last scenario investigates the case of an LED module replacement because of a failure.The findings from the LCA models conducted serve as a guide to suggest eco-design strategies for the environmental sustainability of the new LED modular luminaire listed as several recommendations and reflections along its life cycle.