You will need to consider the siding and roofing materials you would like to use to finish this space. And you might weigh the quality of exterior materials against their visibility. Also in the cost of the addition, be careful to factor in the permits needed and the work needed to prepare the foundation.
Envelope size - 4-3/8 x 5-3/4. Card paper size - 5-1/2 x 8-1/2 (half a letter sized sheet). Finished card size - 4-1/4 x 5-1/2. A4: Envelope size - 4-3/4 x 6-1/4. Card Paper Size 8 x 12-1/4. Card finished size - 4-1/2 x 6-1/8.
The A6 envelope is easily sealed with a moistenable glue strip located on the back flap, and its dimensions make it the ideal 4 x 6 photo envelope. For social and invitation purposes, the A6 is also an ideal large reply envelope size as it easily fits inside A7, A8, A9 and A10 size envelopes.