I am wanting to break away a little for the rectangular sala and see about building one that is round in shape. Has anyone already done this so I don't have to reinvent the wheel? Any down sides, benefits or overall building comments to consider? All assitance and thoughts would be much appreciated. I am thinking of at least an 11 meter diameter, maybe more depending on the engineering limitations. I have 4 rai for a building lot, so plenty of room.