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Building a home cinema extension: 3.5m x 2m - will it be big enough?


Standard Member
Hi all

I have an extension that can max be 3.5m by 2m. I am unsure if this will be big enough as I wanted to have 2 rows of 2 seats which could be a challenge. Does anyone have a similar set up and space saving advice?

I was keen on the recline cinema seats but both rows reclined tip to tip is 3.2 metres and 1.8m across!


Firstly welcome.

As no one else has replied I will give you my opinion. What your planning is a cinema room roughly 11ft x 7ft?

I can't really imagine it working as its just too small. You would be too close to the screen/speakers however you laid the room out.

If your just wanting a bit of an extension with an xbox and 32" LCD on the wall then it should be a good little space. :thumbsup:


Standard Member
I have jiggled with it an dcan get 4m * 2.1m. But I still tend to agree. I set it out using some wood as a floor plan to see its size - length would work but the width would be a little restrictive.

I can get over this and get 3m width but would end up having a back door at the rear or front of my darkedn cinema room. Don't like that idea at all.

Its ok setting it out on the floor plan but by the time you've added the actual walls, insulation, plasterboard and possible acoustic panels you'll probably lose at least 2ft on the inner dimensions.

To make a decent home cinema with a projector you going to want a 7ft + screen and then sit far enough back which I'm guessing you can't do.

It would be nice if it could work I'd just hate to see you spending money on the construction etc and then not be happy with it or not be able to put it to its full potential.


Distinguished Member
The room based on the original dimension is 6.6 feet (2m) X 11.5 feet (3.5m). That is pretty small. While I think you could set up a small home cinema in that room, I'm not sure you can have two rows of seating. Taking some quick measurements of my sofa, I estimate you are going to need 4 feet (1.2m), plus an additional 3 feet (0.9m) for the next row. That place the front or near sofa 4.5 feet from the TV screen assuming the TV screen is wall mounted. Though your head would be more like 6 feet from the screen.

I've got a 36" TV, and 6 feet is workable but close. With a 40" to 42" TV, I'm guessing that would be your limit. Anything larger is going to be too large to comfortably view. But, in any case 6 feet is pretty close.

I think about the best you could do, is one love seat or two easy chairs, near the back of the room, and a small bookshelf to satellites speakers system.

Also, in that tight space, I think you are going to need to give some thought to acoustics. You are trying to squeeze a lot of sound into a small space, and I think that is going to be difficult without some type of sound absorbing material on the walls.

Keep in mind the walls don't have to be covered with sound absorbing material. A few sound absorbing panels place here and there should soften the room enough.

Things to consider -

- What are the floors? Hardwood? Rugs? Carpets? Tile?

The harder the floor surface the more reflective it is. At bare minimum, you want a good rug between the TV and the first seating position.

- What are the ceilings like? Plaster? Acoustical Tile? Textured?

Same as above, if the ceilings are hard and reflective, then you need to find a way to soften them.

- What are your walls like? Windows? Curtains? Other???

Again, it is about reflection, if you have windows in the room and the windows have reasonably heavy curtains on them, that both absorbs and diffuses sound, and that is to your advantage.

The back wall, that is the wall farthest from the TV is the most critical, and the largest bass waves are going to be reflected off of it. This is a good place to put a couple of convoluted (egg carton, pyramid, wedge) acoustical foam to both absorb and diffuse the reflected sound. Though simply putting some reasonably heavy curtains on the back wall would be a good step toward softening that wall, and could make the room look attractive, almost like being in a real theater. Though depending on the final system configuration, you could arrange bookshelf in front and satellite in the rear. That would likely be ideal

Next, in this small space, certainly satellite speakers with a modest Subwoofer would do a very good job. I would prefer small bookshelf, though the difference isn't that much in this space. I personally think that the bigger the speakers, the more air that is going to be moved, and as a result, the more attension is going to have to be paid to room acoustics.

Anything can be done, and every single home cinema room is a compromise. So, the remaining question is, how can you best make a home cinema system work in your limited space?

Also keep in mind that if you have a back row of seats, then it is most common for that back row to be elevated. How much is unclear, but it has to be enough that the people behind can see over the heads of the people in front. And that brings up the consideration of your ceiling height. You can probably just get by with 8 foot (2.5m) ceilings. Higher would be better though.

Oddly, all these considerations aren't unique to you. These are the same considerations that go into every dedicated home cinema room.

Next is budget. If you have give us a general idea of what you are thinking of for a budget for the AV amp and fulll 5.1 speakers that would help us focus more on potential solutions.

In general, the room is a little small for two row seating, and marginal for one row seating, but as I said, we all do what we can with what we have; ever home theater is compromised in some way.

Just a few thoughts.



Standard Member
Bluewizard. Many thanks indeed for taking the time to write this. You are a gent. The answer to most of your questions is that the room is not built yet so I can basically make it to optimise the space. I can follow your tips here - shame there isn't a book on building from scratch or at least a post!

The good news is that based on previous posts I have reorganised the layout of extension. This now gives me 4m length by 3m width for the internal dimension. At the rear I have a door and at the front right I have another door (I basically sacrificed the corridor so that that you have to pass thru the cinema room to get to another store room.

Would you do anything different on your advice with this increase in space? I also need to decide if this is vaulted ceiling up to the pitched roof or a flat roof - would one offer better acoustics (clearly the vaulted is more spacious). No windows by the way although if I go vaulted I would have some blacked out velux windows.

Thanks again.


Distinguished Member
The problem with the doors, is that they could interfere with the placement of your front speaker - perhaps, perhaps not, but it is something you need to consider.

There is a forum here in which many many people discuss their own custom Home Theater installs. You could probably get some tips form them -

Home Cinema DIY Forum at AVForums.com

Members' Home Cinema Gallery Forum at AVForums.com

That should give you some ideas.

As to the ceiling, I would say vaulted or semi-vaulted would be better. Also, textured or some type of acoustical ceiling tile would be beneficial.

The Vaulted ceiling doesn't increase the size of the room, but it does increase the volume. There is more space for the sound to unload into.

If you are still intent on two rows of seating remember what I said, the rear seating will have to be elevated in order for people to be able to see over those in front. Two rows is not impossible, but it is tight.

I would say carpets or rugs between the front row and the speakers. And, a few convoluted acoustical foam tiles decoratively place along the side wall and the back wall. The wall don't have to be completely covered, but they do need something to soften the sound and control reflections.

Room acoustic is a difficult task, as mentioned. On one hand you don't want to over do it and make the room completely dead, but on the other hand, you don't want the room too reflective either. Where the balance point is, is very difficult to determine with any accuracy. But, something is always better than nothing.

Just a few thoughts.


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