Room Lighting Requirement

Hello buds... I am in the design stage of a new grow room, and am trying to source up some basic information. First, how much square foot area would be required for thirty full grown plants. I do recognize that different strains and growing processes will require different size rooms, but I'd be curious to know if there is an rule of thumb for the 'average' sized fully mature plant. My other question concerns lighting. If I chose 600 watt Metal Halides, how many lamps would be required for a thirty plant operation. Would it be a good idea to wire in permanent Sodium lighting for the flowering phase. Thanks for your help

how big do you want your plants to get? do you want 30 1ft plants or 30 8ft plants? answer that 1st. then you can figure out how much room you need. once you know that then you can figure out how many lights you will need.