80sqm on one level is more than an external dimension of 8x10m; subtracting exterior and interior walls, we're rather talking about 10x10m. In addition, the house does not end there, there are also drainage strips, paths, terrace, etc., the affected area is significantly larger. We are building on a 2m height difference on the property and ~80cm from corner to corner of the house still without a basement ( ), but I wouldn't find significantly more sensible. That's why my tip is to take the elevation plan and roughly sketch everything you want to place on the property.