Front Porch Dimensions . Function (s) of your porch. Record each number in a notebook. Porch_C1 Oak Timber Framing from oaktimberframing.com However, after living in an apartment for a while, i realized you. For decades, front porches have been an important section of most of the buildings constructed (residential, commercial, religious, etc). Example plan sizes a b c a cottage porch should have three exposed sides, be no shorter than 7 ft on any side, and be equal to or greater than 64 ft˜ in area.