My observatory is a wooden structure, 8’x14’ with a fiberglass dome. It is on a farm about an hour from Minneapolis.
 
Observatory
Starhouse Observatory
I love my observatory. It is my pride and joy. It is a fairly simple design. The dome, a Home Dome, is fiberglass and 6’ in diameter. The structure is wood framed with concrete footings. The pier is a 16” diameter concrete pier with a steel AstroPier on top.
Observatory Photos
More Info
Blueprint
I used to power it with a solar panel and battery but my power usage has gotten too high so I use A/C power from the house. We also have a wireless network set up so I can control the observatory from a warm room a couple hundred feet away.
The mount is controlled by TheSky by a serial interface to my laptop. The camera is hooked up via USB. I use CCDSoft for image capture. Because it is linked to TheSky the resulting FITS images have the object position, the airmass and other useful info written to them. I also use TheSky to plate solve the images and add WCS headers.