room placement question

I'm looking into buying a new house and I'd like to make sure that the room I choose to place the speakers will work well (unlike my current place where I didn't think about this at all).

I have seen a lot of floor plans that look similar to the one in the link below, and I just wanted to see what are people opinion on how well the speaker could be placed in the "great room".

I was thinking of placing the speakers on the window wall, but my concern is that there's a solid wall on the left side of the room, but on the right side of the room there is no wall since it opens to other parts of the house. Is this lack of symmetry something to be concerned about?

Yes, you should be concerned. There have been numerous threads by people who have imaging problems caused by asymetric rooms, especially where the side walls are not the same distance, length or material. I would strongly recommend you avoid that situation if possible.

On the plus side, the room ratios and cathedral ceiling are all quite good, especially if you put the the speakers on either side of the "optional fireplace". If you could extend the dinnette wall well past the right speakers reflection point it might work acceptably well.
Thanks a lot Zargon. That's pretty much what I was thinking, I just wasn't sure. Also, I'm guessing the lack of a back wall shouldn't cause any problems (since I'm assuming the reflections off the back wall wouldn't be something desired anyway).
You might want to consider listening more near field if possible in order to avoid undesirable room effects. Small monitors would be a ggod fit for that.

Or the other way to go for a wide variety of potential listening locations would be with omnidirectional speakers that radiate sound in all directions. This will tend to fill the entire room with sound more evenly and lessen the effects of openings to the side and such.
I probably should've included what speakers I'll be using... I currently have Dynaudio C1 monitors, so this would go well with Mapman's suggestion of listening more near field.
Shortwall setup, eliminating the 'optional' gas fireplace seems to be the concensus.

Experiment with diffusion / absorbtion between the speakers and on the long walls next to the speakers.

Asymmetric rooms have an advantage in bass. In my really awful room, bass nodes simply are not obnoxious. Too many walls, too many non-matching dimensions and some 45degree angles.
I don't think it would be as bad as some speculate. Other than this questionable it seems to be an excellent space.

I'd suggest 3 things. 1) Install solid wood panel sliding double-pocket doors between the great room and kitchen. 2) modify the main entry to the great room so you can install another set of solid wood double-doors (pocket or swing into the room) so you can have privacy without completely annoying others. The solid would double pocket doors should absolutely minimize any concerns.

3) I suggest talking to the building about using the unexcavated space under the garage as a dedicated media room with maybe a 9 or 10ft ceiling. Very isolated, probably concrete walls, floor, and ceiling. It could almost substitute as a bomb shelter. :) That's the space I'd set my sites on. Just make sure they shore up the ceiling really well.

I feel the asymmetry problem may be overstated. Along the short wall you could put the speakers 7 feet apart with 4 feet to spare on each side, which should be plenty to avoid strong reflections, especially if you treat the first reflection points.

I don't have any axis of symmetry in my room but am still able to achieve an even soundstage by keeping the speakers well away from side walls.

unexcavated means there is no space below the garage. It means no earth was removed.
I looked at the plan drawing and think the unexcavated space should stay that way.....The garage floor is doubtless poured concrete. To make the space under the garage usable would require some real engineering and LOTS more concrete, not to mention plenty of steel. All 6 walls would end up as concrete with the attendant problems making it sound OK.....
Doable? yes. But you'll need an engineering firm and plenty of CASHOLA. This won't be a simple shovel it out and move in proposition. Depending on where you live and various zoning / regulatory hurdles, it could turn into a mess.