I built a small treehouse for my daughter 10 years ago when she was 7, which she has outgrown. My son wanted to use it, but it featured a rope-ladder to access it. This led to the potential of falling from the platform all the way to the ground. Not good for a 4 year old! So I decided to update it and add a series of platforms to allow younger kids to climb up it in smaller stages. Much safer, and now it has more room to boot. The platform is completely open at this point, I am sure it will get walled in and turned into a clubhouse at some point.
The 2x4s for the swings were a late addition, they work for 30lb kids, but will be swapped for 4x4s soon.
I've never attempted something like this but my kids are getting to the age where they would really appreciate it. Did you start with any specific plans, or did you just add on as you went along?
I built a 4x8 platform first, surrounded by a railing, with a rope ladder. You can see the darker wood that has been out there many seasons. After a few summers, the railing gave way to plywood walls and a ceiling with a skylight.
For this update, I removed the walls, added the 4x4 posts, and topped them with another 4x8 platform. The wall is made from dog-eared fence posts cut in half. I specifically built it so that the inside surface had nothing for little toes to climb up on.
I used no plans specifically, just kinda made it up as I went. In hindsight, having a plan would have eliminated some issues and made better use of lumber.
