I pulled these from Jautor's build thread, some really good points, hope he does not mind.
"LESSON/MISTAKE: Having the risers built-in as part of the structure means it's not possible to undo the theater and turn the space into something else. Not that I would ever do that, but it could be a turn-off to potential future owners. While it would be possible to fill in the front of the room, lowering the rear riser would be a huge challenge."
"LESSON: At the time, Dennis' AVS-special design service wasn't available, and having shopped for other design services (which I deemed too expensive at the "basic" service level for the amount of additional expertise I would gain), I didn't use any of them. Having seen Dennis' design work here, and for the price he offers the AVS service, I *HOPE* that if I was starting from scratch today I would be smart enough to send him a check! I did get a lot of free advice from industry experts and manufacturers by visiting them at CEDIA, and of course, reading lots and lots of AVSforum threads. "
"MISTAKE: Having the risers built-in as part of the structure means it's not possible to undo the theater and turn the space into something else. Not that I would ever do that, but it could be a turn-off to potential future owners. While it would be possible to fill in the front of the room, lowering the rear riser would be a huge challenge.
MISTAKE: I also made the risers 5'9" deep, also using some chair dimensions (see LESSON above). In the final theater, there's just enough space for the Berklines to recline fully. "
"IF I DID IT OVER: I'd have made the room 17'x 24', adding a foot of width (6" to each aisle), with at least 1' longer to the front, and 6" more on each riser. But I would have stuck with my final seating plan. If I had the room up front, I might have put in a small stage, but I don't consider the lack of a stage as a mistake, either."
"MISTAKE: Plan all your speaker locations before the room shell is constructed. When I built the house, I had a space in the back for a pull-out rack, so rack access wasn't going to be a problem. And I made the rack area large enough for a small countertop - likely for a popcorn machine. But I didn't think about where the rear speakers needed to be. Turned out one of them really needed to be in the middle of that cabinet area. If I placed the speaker column inside of the cabinet location, the two rear speakers would be only 4' apart. Nope, speaker placement wins, cabinet goes away. In hindsight, that cabinet was unnecessary. Popcorn machine is hot, noisy and smelly (all in a good way!) - and is therefore better off outside the theater. I had a lot of U space in my rack, so I added a drawer there for remote/accessory storage, which works great."
"IF I DID IT OVER: The rack area will later be drywalled with everything else. But the AX-S pull-out rack is intended to be used with "millwork". I should have finished the rack recess area with a site-built cabinetry box. The small, drywall covered space isn't perfectly square/flush, so when I pull the rack out, it tends to rub on one corner, which makes me get out the touch-up paint. A cabinet could have been made easily to the proper dimensions, and slipped into place. I purchased the Gasket/Guide kit for the rack to fill any gaps - turns out I don't have any gaps, it's too tight a fit even for the guides!"
"MISTAKE: (This is the big one, which is great, because it didn't really impact the final outcome) aka:
IF I DID IT OVER: The columns, all 6 of them, were then framed out to be covered in drywall. This meant that the interior of the column is outside the treated theater space, and therefore all the things penetrating it are creating holes in the theater. Little things like the step and sconce light electrical boxes. And, um, that in-wall 6"x12" speaker. D'oh.
In hindsight, those columns should have been built post-drywall, with only small holes for electrical and low-volt. Thenn the speakers would have been enclosed within the room. The result is that as they are, a lot of surround sound can be heard in the attic space on one side of the theater, and it's also transmitted from the rears to the stairwell behind the room. The good news is that because the theater is placed away from bedrooms, and it's only the 'surround' channels, it had no real negative consequences for me. I may box in the side columns from the attic side to reduce transmission there, but it's only a nitpick for me. But your milage would definitely vary...
The same is true, to a lesser extent, of the ceiling framing. The can lights also penetrate the room shell, not a post-sheetrock soffit. But again, this is a second floor, the attic above is filled with blown insulation, and is geographically isolated from the rest of the house. In the end, with music playing at high volume from all channels, I can barely hear the transmission outside, and not from the bedrooms. Most of the sound that does make it into the adjacent gameroom is coming through the solid-core theater door (you can feel it vibrate)."
"IF I DID IT OVER: I would have used two separate PowerBridge inlets behind the rack, one going to the projector location, the other to the front of the room (for speakers/subs/screen). The reason is that if I wanted later to install a UPS in the rack for the projector, the way it's wired now, the subwoofer and everything else at the front of the room would also be on the battery backup. Had I wired separate inlets, I could have run the projector to the UPS, and the screen wall outlets just to the conditioner/surge protector. Now, this is probably not a big deal as it is, as "run time on UPS battery" is not the goal here."
"IF I DID IT OVER: Since the GrafikEye will be installed in the entry hallway, I decided to add 2 wall stations where one would expect the light switch(es) to be in the room. One just inside the room, and another next to the rack. In reality, with the remote control working well, I rarely use those wallstations, and at ~$200/each probably would have skipped at least one, if not both of them."
"LESSON/MISTAKE: With all the recessed lights on, it's still not bright enough in the room to read comfortably from the seating locations. Not an issue for theater use, but I ran into it many times with instruction manuals! I can crank up the sconces, but the direct glare from those at full power doesn't help the situation.
IF I DID IT OVER: I probably would have added 3" recessed can lights in the soffit above the seating locations, which of course would also have helped force me to the 8-zone GrafikEye."
"My advice is to follow what I did (based on advice from other AVS'ers):
1) Wait until the room is complete before actually buying the projector
2) Wait until you have the projector before finalizing the screen size
3) Test screen size in the real space before hitting the "Buy" button..."