Jehan de Maille : hey Saskia.....i'd definitely be careful to NOT make a decision based on sketch up.....depending on the size of the plot and its degree of elevation....sketch up seems to go crazy.....1 easy reason is that g.earth is not THAT accurate on elevations.....for my exercice, i finally had to drop sketch up contour lines, they just did not make sense once on the terrain....(fairly flat land) you might want to use that a-frame, transit level or laser level before commiting to dig......

Cindy Madou : Hi Saskia, may I conclude you've got the plot you talked about earlier ? If so congratulations! I must agree with Jehan that Google earth is not very accurate. If I should believe Google earth my property ends on a vertical wall with a hight of 2m, which is definitely not the case. But it was still useful to get a better idea of the larger area ... And you did gain some computer skills ;-)

S. Symens : Cindy, normally we should get it, the bank approved our loan, we're waiting for the notary to finalise the data :-D As far as I can judge it, not having access to the terrain until the deed is signed, the Google Earth Sketchup combination is more accurate than any topographical map I've seen so far, but of course, I will be checking my plans with an A-frame! Thanks for the warnings though, both of you!

Cindy Madou : Wow,spannend! In which area is it ? I'm a very curious person ;-)

Lorenzo Costa : Great to hear Saskia about the land. I ended up not using google earth it just didn't work well after one year of walking on the land I knew there were some things that were different. I used this link and method, try it: http://www.permies.com/t/35897/web-sites/Tutorials-permaculture-design-free-software especially read part 4 of the tutorial, its quite an easy system that was more accurate than just simply using sketch up. I'll admit that anyway I'm goingo to laser level everything this end of summer. I want to be sure I have the terraces and I want to be sure how they are built

Lorenzo Costa : http://www.permies.com/t/35897/web-sites/Tutorials-permaculture-design-free-software

Jan Åberg : If you think you need the fine details, you can ask a local geographer if there are laser-scannings available of your land. Because if that is the case you can use a GIS-software to extract very accurate contour lines (I use free software such as SAGA-GIS or Qgis). In my country (Sweden) the price for the laser-data ("Höjddata 2+") is very low in comparison to the amount of work required to measure the levels "by hand".

On small blocks of lands (such as your block), you should also try to use the simple tools suggested in the "Designers manual" when you do earth-works. Start in zone 1, and then let the pattern emerging in zone 1 show you how to design the details in zone 2 and so on. It will take more time, but is it wasted? I don't think so, because you'll also use the time for observation.

Corey Schmidt : beautiful image : )

S. Symens : Cindy, the land is located halfway between the cities of Leuven and Diest, in Vlaams-Brabant. Lorenzo, thanks for the link, I'm only now getting around to it! Thanks, Jan, these are all very sensible things to do. I like the organic approach too, starting from zone 1 and letting it grow... :-)

S. Symens : Thank you everyone, for your good advice and legitimate warninfs! I finally redid all of the contour measurements with an A-frame: the Google earth ones were so wrong as to be unusable!