Our cottage design plan 24 x 26 has a gable roof (6/12 roof pitch). Planning to add a deck 20 x 8 and want to have a cover over the deck. Is the most economical way to add a second small gable to the roof rather than an extending the roof? Are there any design guidelines that it should be gable style on a gable roof or are there other roof styles that complement the gable style? Thank you.