I am the type of person who has to plan every detail before I get started so it is no surprise that this project took a while to plan and only a couple of weekends to build.

It all started with the graph-paper plan (view image for particulars). I changed the layout a bit during construction which is highly unlike me, but it was for the better.

The design is a 12' x 12' (est 3½ meter x 3½ meter)

My garden shed had two 6' sets of doors and one was really unnecessary so I used it to attach the greenhouse, give me access to greenhouse form shed, and allow all those carpenter bees that are boring in the rafters to have easy access to the plants in the greenhouse. Sure, they may make my roof cave in one day but my cucumbers and tomatoes will be pollinated well in the meantime.

Using some graph paper, I drew out my outline. I used 4x4 treated posts for the main verticals, dug 2' in the ground, concreted, and with right at 4' on the insides of beams (not on centers). I did it this way because of the width of my windows. My windows were picked up at a local salvage yard for $35 each and 4'x6'. I wanted the 4' part to be my width and the 6' part to be my height so the uprights are 4' in between each.

Note: MAKE SURE to get your base square. You are perfectly square when the measurements of your diagonals are the same and your widths are all the same. Take the time to do this and it will prevent headaches later.

Next I planned the roof layout. My roof was not going to be as heavy since I was using 12' polycarb corrugated panels. I only needed a center board that would support the entire weight (I went with 2x8x12) and then used 2x4x12's to run on 2' centers (the recommended width for the roofing panels).

Look at comments on pictures for some additional insights on initial startup.