Terramara was an ancient house dated in the Bronze Age, built by people leaving in the central Po valley, in the northern part of Italy.
As my sons asked for an house on the tree, and as i considered it too dangerous compared to their ages and the height of it, I switched them to a "terramara".
Basically it's a palafitte with a house on it, and I modified the concept building a simpler structure, more similar to a kind of balcony for birdwatching :)
But for my sons it's a "terramara", indeed.
Approaching it with engeering concept, I first had a look at the available (and not too expensive) materials I could find in stores in my areas. Avoid places as OBI or Mr. Briko: materials are low quility, and quite expensives. I found what I needed on building materials stores. Not much choices, but there was what I needed.
I got two different basic materials. What we call here "morali" (8x8cm poles 4 meters lenght) and scaffold boards (30x4cm, 4 meters lenght). Then I had only to write down a project suitable for what I had.
I first draw it, and after some write and scrub, I decided to move to Google SketchUp: free, easy to use, and project was easy to modify as I thought about it.
[to be continued]