Finished two of the projects for this summer - the well house and the big barn.
Closed in means that the roof is on, and the walls are complete, and it's weather-tight. Work still needs to be done, but it can be done inside, out of the rain - and on a non-emergency basis. It's always nice when you can choose the time you work on something, instead of having it chosen for you :)
Plywood sheathing is expensive but it holds up a lot better in wet and damp environments, and the wellhouse is pretty damp and cool most of the year. Plywood is $19/sheet, OSB, a more common alternative, is about $8/sheet
I framed the wellhouse with 2x6 to allow space for insulation and to be able to bury the plumbing in the walls if I chose. Most of it I left exposed for easy maintenance. the old wellhouse is in the picture above, to the right on the bottom. The new wellhouse is about 30" above grade, the old one is built on grade. the old one floods - the new one won't.
I had some sheets of siding from the big barn project - so I used that, and some trim, and picked a door that matched the existing door on the dairy office for the farm, so it has a nice consistent look with the rest of the outbuildings.
It looks a little odd with the door set to the side, but that's so that I can stack pallets of salt to the left of the door. The local hardware store gives a much better price for salt when you buy a pallet at a time, and I use a fair bit of it to soften our (very hard) water.
This is the south face of the barn. Man door on the far left, 16'x23' sliding barn doors in the center. The yellow bollards are there to stop people from running into the door frame with equipment - hopefully they won't, or the bollard will prevent damage :)
This picture was taken as we applied the last bit of skin to the barn. The top 3' of the east and west walls are clear panels, and they provide plenty of light on the inside so you don't need artificial light during daylight hours. Much more pleasant (and cheaper!) to work with.
The barn itself is 250x100, and it's clear-span. No pillars or anything in the center. The ceiling in the center (measured from the floor to the lowest point of the structural steel, is just shy of 20'.
I include this picture of us attaching the barn doors and adjusting them to provide a little bit of scale. Its really hard to see how big this barn is until you put two people on top of one another, and can have a 3rd and most of a 4th and still not hit the top of the barn. I rented the manlift, and was glad I did. Would have taken much much longer to do this with ladders or scaffolding.
We have two strips of concrete to pour in the big barn to complete the floor, but that can now be done anytime - we have a roof and walls, and can heat the space if we need to.