Idea for growing room

In my tiny house i have no room on the main floors to grow. I have a access to my attic in one of the rooms closets and the attic it leads to is pretty big. Big enough to grow a couple plants. Now i have read a couple of the other threads about attic growing and a lot of grow guides but i thought i would post my ideas before i construct my grow area. I will only be growing 1-3 plants at a time for personal use and to share with a couple of my buddy's. I would be fine with one plant if that will be easier to accommodate considering the situation. I was thinking of making a Little room inside of the attic to make the controlling of the climate a little easier. I was thinking of making the Frame of the room out of PVC pipe or 2x4's. It will be somewhere around 5ft high, 3 ft wide. The Areas in the frame i will build for the room will be sealed with probably tarp or a like material. I have the watering situation under control. The lighting i will use will probably be 2-3 2FT UV lights i have left over from past grows. I am not sure about the ventilation i should use for it though. I was hoping to obtain a couple ideas from some more experienced growers on this site. Would a couple fans in the side of the little growing room be enough ? I would like to try to keep the amount of electricity used on the lower side considering i am not made of money. If you have any suggestions please feel free to share them with me. Thanks for your time and help.