The question is, is it better to have 2 smaller Gable additions or one big one? This is a 1960’s simple Gable roof and the trick is how to add an addition off the back ?
Adding a big Gable winds up being higher then the original roof and there is a lot of wasted material in a bigger roof if a pre-fab truss is used (which is the cheapest building method).
The double gable is smaller in scale. Verses a large gable that extends up past the existing roof.