If you live in a nice, safe location, and don't plan on moving anytime soon, you should build a grow room. (with wood, and insulation, not PVC and mylar).
If you live in an apartment, or see yourself moving in the near future, a grow tent is worth the investment.
I found this out the hard way after moving a bunch of times and constantly scrapping my constructed grow rooms. Wasted a lot of materials before biting the bullet and purchasing a tent that can be broken down, stored, and moved from place to place.