An investigation was carried out under urban conditions during two successive autumn seasons (2022 and 2023) at the Central Laboratory for Agricultural Climate (CLAC), Giza, Egypt. The objectives included the effect of five different N levels (80, 100, 120, 140 and 160 ppm) of nutrient solution combined with two pots volumes (6 and 8 L) were investigated on lettuce (cv. Robinson F1 hybrid) plant under an urban condition in a split design. Agronomy and food security concern, increasing substrate volume from 6 to 8 L / lettuce plant led to an increase in the vegetative growth and yield parameters as well as an increasing nitrogen concentration of nutrient solution from 80 up to 140 ppm. Substrate volume 8 L presented the higher significant records of vegetative, yield and nutrient contents values plus nitrogen use efficiency (NUE), as the revealed results indicated. Similar trends were obtained by nitrogen concentration of 140 ppm of nutrient 
solution that gave the highest significant results. Sustainability point of view, substrate volume 6 L/ lettuce plant combined with nitrogen concentration 80 ppm of nutrient solution achieved the environmental objective by providing the lowest NUE and natural resources while had the highest net profit on the economic scale instead of the lowest fresh weight of lettuce yield but with the same number of lettuce per area unit (12 lettuce plant / m2). The study encourages investigating alternatives of chemical nutrient solutions in case to maximize the economic scale of urban farming as well as match the sustainability.