Now that the other walls are up, it's time to focus on the front wall - which will contain the doorway. As you can imagine, this is the most time consuming to construct, because it has alot of detailed parts, and they have to be the correct size!
A stud has been installed on each end, and also 16" inward. This is when it's time to find the location for the door, before going any further. In the picture above, you can see how the wall will be placed, and I want the doorway to be centered. With that in mind, I marked the exact center of the last wall to be built, then made another mark 3 1/2" to the right. This last mark will be where the center of the door needs to be located. Once the center was located, simply measure out from this mark in both directions, and make the outer edges for the particular opening you'll have. Since I'm planning on installing a 32" wide prehung door, the rough opening needs to be 34 1/2" wide. The small pieces of 2x4's mark the locations of the intended rough-in components.
Photo below - here are the king studs, and jack studs in place. This will be the rough-in opening for the door. Notice the studs on the inside (jack studs) are shorter than the king studs....This is because the header will rest on top of them.
Photo below - I've placed a couple of scrap pieces to give you a visual of how wide the header needs to be. Since the top plate isn't installed yet, the only place to measure is here.
So, let's make a header for a doorway. A header is a really beefed-up piece that spans across the top of the doorway opening, which keeps the weight of the roof from sagging at this point. It is really important to build one for door and window openings. Since the header has got to be exactly 3 1/2" thick, (the same as the width of a 2x4) it takes 2 pieces of 2x6 board, and 1 piece of 1/2" plywood sandwiched in between to get this thickness. The 2x6's were cut first, then one was used to mark the cutout for the plywood.
Photo below - Here are the three pieces, ready to be assembled.
Photo below - My little helpers are used to keep the pieces in place, where they are nailed together with 16d nails. You want to place a couple of nails about every 6" or so....