The roof has a 28° (28 degree) slope, which might seem like an arbitrary figure - why not use 30°, which might be easier to draw? Well, I'm trying to get as close to a total 4m height (the legal maximum for a shed) as possible, and that includes the floor, and the concrete pillars below, so any extra roof height would have to be offset by lower walls. Changing to 30° would add about 8cm to the roof height, and if I lower the walls I have to lower the height of the doors. As I am 6'9" I am determined not to compromise on door height!

It would also mean that the rafters need to be almost exactly 2.4m long, which leaves no leeway for trimming the ends of standard 2.4m lengths (eg if one gets some slight damage or is too short to start with). At 28° they are 2.35m, so I've got 5cm to play with. I could order 2.5m wood, of course, but that's non-standard so will cost more and may not be in stock at short notice. These are all things I've had to bear in mind during the design of the shed.

It was my original intention to build the whole of the gable end in one piece, so the vertical struts would stretch from top to bottom. Fine for the front and left gables, but the one at the right of the shed would be a problem - it's part of a longer wall where the two sections of the 'L' shape meet. I envisaged complications, so now the plan is to build the whole of the wall structure first, then add the roof later.

The louvred vent is essential for ventilation - if you don't have ventilation the shed roof will rapidly deteriorate as moisture builds up and has nowhere to go. I will be building these vents myself from scratch so hopefully will add a plan for one at some point.