In a Loft?

Hey guy n gals im a newb and want to get setup in my loft, what's the best way to do it safely?

Start small and simple I always say get a feel for it. Do a lot of reading on this forum and any others you use to get familiar with growing. Use like a 250W HPS some good soil and a closet

Does your loft have a good air conditioner? I grew upstairs once and it simply became too much of a hassle to keep temps in check. I ended up moving downstairs. A grow tent definitely helps with the heat signature if that's what you're worried about. They also sell insulating covers for hoods that not only block heat signatures, but also lower the temps in the room.

start small..... but stay small toooooooooooooo!!!!!!!!!!!!!!!

It has no air conditioner, I was basically going to build an mdf box with a extraction fan and a intake fan built in. Hopefully I can get the tubes to go out side, but I'm only renting so don't want go tearing the roof apart!! Thanks for the input, if anyones got any tips I'd be pleased to hear them . . . or read them

And how small is small?