Confused Over The Best Way To Punctuate

I was wondering if anyone could suggest the best way to punctuate a sentence with the following construction:

"The third pig built his house out of brick and stone, making it far stronger and sturdier than the others so it would not get blown down as easily."

Basically, the thing that caused me some deliberation is whether to have a comma between "others" and "so". On the one hand, "so" introduces a subordinate clause meaning that a comma would be unnecessary. On the other hand, when I start thinking of the middle prepositional clause—"making it far stronger and sturdier than the others"—as parenthetical, the use of the comma makes more sense.

Are both right? Do you think one way is better than the other?