Private studio sizes and features: What works, what doesn't?

I'm strongly considering relocating for work in the next year or so, which will also be a great time to upgrade my living arrangements, and I figured that I may as well start considering what I want in a new space.

First and foremost I find myself wanting an area that can be easily used as a photography studio, and possibly something I can configure to work as an old school dark room for enlarging large/very large format prints if the budget allows. (Which will likely involve enough work with a horizontal enlarger and space to custom coat papers/plates)

I really haven't done much work in a studio like environment, and while I can guess what would work it would be foolish not to get input from others. What flaws do you find are common? What features do you wish your current space has?

For size, at what point do you find you have enough room to work freely? Have you ever worked in a space and found yourself thinking "This is way more volume than I would ever need"?

Currently I'm thinking that a goal of a space 20-30 feet wide, 30-50 long, and with ceilings as high as I can get them should be a good target. In all likely hood the space is going to double as the main living area of the house, but in that case I will modify or custom build everything such that it is simple to reconfigure out of my way.

Thoughts and opinions?

What do you plan on shooting in your studio? That will be a huge determining factor as to how much space you need. A studio for shooting cars would be very different and much larger than a studio for shooting small products. If people are to be your main subject, it will also make a big difference on how many people you would expect to shoot at a time and if full body photos are wanted/needed. For instance, a large family in studio will take far more room than headshots for an actress.

That.

You got a studio set up? Small, big? Show us how it looks like!

Pitfalls with first Studio?

What do you think about a Garage Studio