My observatory has a rather small 8' x 12' footprint but by careful design I was able to include a small warm computer room and two piers in the main room. Six sonotube piers are the foundation for the building while two massive square piers anchor the metal piers for the mounts.
The gravel bed is one foot deep and is used by the passive cooling system to cool the observatory in the summer.
Here we see the finished floor framing. The floor is, of course, isolated from the cement piers used for the telescopes. Screening has been attached to the bottom of the framing to keep insects and critters out. The tall plastic pipe brings power to the observatory while the short pipe connects the telescope room to the computer room.
Since only one step would be required to enter the observatory, I hung the framing for the step off of the deck framing. The entrance step thus appears to 'float' above the ground.
I like to work with wood, so I got some fresh cut native oak and built a post and beam frame. All of the joints are mortised, tenoned, and pegged.
It's often the details that make a structure. In this image, you can see some of the ones that I used: saddle joints, half lap dovetails, and chamfers on the beam tops.
I like to keep things simple, so to open and close the observatory roof I use a single split drum winch. In this case, I simply modified a reversing winch into a split drum winch.
I recently built a walkway to the observatory. Click here to see construction details.
Another recent addition is an oak counter for laptops and notebooks (the pencil and paper kind). Since I'm always standing when using these, I put the counter conveniently high.