Here is a post from a builder who suggests framing lumber straight out of the lumber yard.
Just got through with the 4X8 playhouse and thought I'd pass this along. First I made all of the cuts per plan at a friends house and had no issues. The second is by doubling the uprights to the right of the door I was able to cover all of the sides with a 50 foot roll of 36 inch wire. Everything was ripped from 5/4x6's but I cut extras to cover ones that may have warpped. If I built another I would use a full board there instead. Just thought I would pass it on and will try and update to the blog if it's ok.