I happened to see this design (or see below) for a pergola, and I thought, "What an easy way to have a Sukkah frame up all year round!" But then, when I noticed that it only has a depth of four feet, I realized it wouldn't be large enough to entertain. But then I thought, what if one were to put up two of these pergolas, facing one another, with about a two or three foot gap between them, and lay bamboo across the top, so that it also covered the gap? Then you'd have a Sukkah that would be, without any gap, 8'x12', or with a two foot gap it could be 10'x12'. Now you're talking about a pretty roomy, and attractive, Sukkah! But what about that gap? Sure, the Sechach is covering the gap at the top, but would the gap in the walls be a problem?
(As an aside, although I should really look into it more closely to be sure, I'm fairly certain that the walls themselves are acceptable, because a fence of a similar structure is used for an 'Eruv that has been approved by my rabbi. Hence, I'm only asking about the gap. If you see a flaw with the walls themselves, feel free to point it out in the comments, but also realize this is an academic question, as I do not intend to purchase two, or even one, of these products, given the cost, and I'm just curious about what is valid vis a vis a gap in a wall. So, if you do see a flaw, just assume that the same structure can be made with an improved wall, yet the gap would still be at issue here.)