Why yes, I do grow in the attic!

My setup is 2 parallel long rooms divided by a double layer of mylar.

Each room is app. 10x5feet.

The far room is for flowering and has the window in it.
Window is sealed over with a layer of tinfoil and then a layer of mylar.
There is a small 8,000 BTU a/c in the window, and I made a baffle out of mylar to avoid light leaks.

The door to the flower room is just a couple layers of thick plastic, and is closed during lights out, and open during lights on for ventilation.

Lights are 1x400 MH and 1x400 HPS in the flower room in summer.

In winter the a/c is removed and replaced with an additional 1000 HPS.

Mature plants are placed in the MH end of the flower room until sex is shown.
The longer the plant has been in flower, the further to the right it is moved so it finishes directly under the HPS.

It's a perpetual-cropping system.

The veg room has a tall steel-wire rack with 4' flouro tube fixtures for seedlings, clones, and small plants, plus a 4x4' area of floor space illuminated by 1x250 MH.

I'm getting another 400 HPS soon and putting the 400MH in veg.

I keep mothers, immature plants, and all my tools in the 24h veg room.

Ventilation is simply a large fan in the open doorway to the veg area.

There is no odor control, since my house is a 3 1/2 story Victorian in a breezy area and the wind carries odors away before they hit ground level.

For containers, I seed into 60mL nursery 6-packs with a fine soil of topsoil, vermiculite, and composted manure with humus broken up to a fine tilth.

The next stage, when seedlings are big enough to be moved and fed, is in a mix of 30-50% perlite, composted cow manure with humus, and maybe some topsoil if I have any extra laying around. Plus myco-stim. Not very scientific... The containers are 5x5x6.5 inch square DEEP nursery pots.

The next stage, when plants are going into the flower room, is in 10x10x18" square deep plastic buckets. Soil is the same as before, with additional organic amendments: Guano, Fish goo, and a pinch of lime.

I am getting big muscles from carrying dirt up and down 3 flights of stairs.

One thing I am tight on is that my plants HAVE to perform in 8 weeks:
8 weeks seed to maturity, and 8 weeks 12/12 to harvest.

Temps are a problem if I don't keep an eye on things and on my wish list is a high/low temp shutoff and high/low dual outlet to turn the heating and cooling stuff on and off.

Humidity never gets above 50% with the a/c running, even in our muggy nasty New England summers. This may be in part because I am so stingy about watering and let my plants go almost dry before feeding, but I do NOT need to have any mold problems. Allergies, you know? I usually have %RH around 35-40.

That's my op in a nutshell.

When I'm out of exile (I rent out part of my house) and get my basement growroom back, I'll be only vegging in the attic for temperature reasons.