New Theater Room Construction Help

At the planning stage you'll need to decide to what lengths you're going to go in the pursuit of soundproofing/sound isolation. If you're looking to soundproof, you'll want to keep HVAC ducts to the rest of the house from running through the ceiling of the room, and you'll want to plan on building dead vents for any vents and returns that supply the room.

6" step is probably a little on the shy side but it depends on the position of your screen, etc.

>>1.Given the above criteria, what is the minimum room size (WxL) that is necessary?

That depends on the answer to (2), and if you're using an acoustically transparent screen (which adds 2-3' depth). Assuming an AT screen with 2' deep false wall, three rows of recliners spaced 7' apart, and 11' first row seating to screen distance, it would be 27' or so long. My room with 4 across curved seats in the back is 17' wide, and that works pretty well, still enough room on both sides. So maybe 27'x17'. If you use barstools in the back row, you can deal with just one riser (bar stools sit higher than the recliners on the same level), and cut down on room depth a couple feet.

>>2.How far apart should each row be from the other?

That depends on the type of seats - if recliners, figure about 7' between rows to allow for recline and ability to get to/from your seat. If not recliners (typical movie theater seats, or couches, etc.), will be less.

>>3.How high should each step be? Is a 6" step enough?

That depends on how high your screen is mounted. There is a riser height calculator that you can use to estimate; mine ended up being 12" high for the second row, which was just enough to be able to see the bottom of the screen from the second row, over the seats and heads in the first.

>>4.Any other details that is necessary for us to know at the planning stage?

It depends One thing that comes to mind is you may need multiple side surrounds to provide adequate coverage for the three rows.

Have you considered using the Pro Layout Service? Take a look at least. Although I am happy where I ended up with my build, my build would have been accelerated significantly if that service had been available at the time - a lot of time spent researching and waffling on decisions, vs. following a well thought out plan.

Also, take some time to browse through some of the more popular (# of posts, # of views) build threads here for ideas, you'll pick up a lot of ideas that you might not have considered, that you can integrate into your plan.

18x30x10 ft ceilings, each riser will probably need to be 12 inches tall.

If that is too big think about a sit at bar (facing the screen) for the third row and you could shave 4-5 ft off.

Door position is CRITICAL for an effective layout so where the room sits make a difference.

If you would post a measured diagram of the layout of the basement and location of columns you will get some suggestions of how to position a theater.

Actually, as long as they're not contacting the final ceiling, and the ceiling is decoupled with damped mass, and you don't pack in the insulation around the ducts, they're generally OK to leave.

Certainly agree with your points about the ducts that actually supply the room.

The simple answer is, everything should be known at the planning stage!

12 to 14 people is 6000 to 7000 BTU's of cooling ... electrical, HVAC, sound isolation and full construction prints are needed for your contractor or architect at this stage or you're likely going to face compromises, or additional expense, later that could have been avoided by earlier planning.

Personally, I would really avoid that - you change your mind on seating style, requiring different riser depth(s), and you're stuck with it.

I would only consider pouring a stepped down floor if I had a professionally designed plan that you liked and are willing to stick to it, There have been plenty of guys showing up in this forum with something they developed with the advice of their builder/architect and it was basically flat out wrong.

Dennis could help you.

The best solution is to just lower the entire floor in the theater space and build risers as part of the theater construction.