Efficient way of 3D Site Modelling in Rhino

[wim (Wim Dekeyser)]

Hi Claudia - Robin has listed a few good points.
You write that you are importing a map but that could mean many things.
Sadly, it doesn’t look like Openstreetmap has a lot of building height information, else you could have just used that.

In this picture, only the building in blue has some height information; the ones in green are at random height.
The dataset is downloaded directly from Openstreetmap and turned into Rhino geometry by means of Tim’s Grasshopper definition that is found here:

Boston OSM Heights

Not the best example, because there is much randomness, but the first one I found on my Computer. [elk_city] As you can see, some numbers have a m in the end. So I needed to remove them. [elk_city_1] Or one Building, had also underground levels. Didn’t needed them, so I removed it. [elk_city_2] And the Buildings where I hadn’t any height, were extruded by random numbers. You can choose the Domain, so it fits to the existing ones. But you Need nearly always to search the text for Errors…

Orsman Road, London.3dm (2.4 MB)

Going from something like that to the picture that you posted will require a lot of work.
-wim