Hello everyone,
My name is Thomas, I'm a student in architecture (3rd year) at the university of Liege in Belgium and the answer to this question may actually help countless students in the futur

For all the projects we have, the teachers give us reference dwg of the context with elevation data (they use LIDAR) as well as cadastre data. Those are actually part of a continuous map of all southern belgium (PICC : informatic project for continuous cartography).
Here for example the city of Liege : http://we.tl/ASHA1b8qeY
(I used WeTransfer for hosting because the file was too big to be attached)
I think it's just a cloud of points which are linked with poly in order to make sense in plan view but is a pain to read in 3D

So the problem is that no one in school (including the teachers apparently) knows how to deal with that data. So all we've been doing for years is :
in autocad : 1)flatten the image 2)recontour manually what interests us 3)import to sketchup 4) click on each line to get the height data in autocad 5) extrude plan in sketchup with the height data

As you can imagine, modelling parts of the city we work on takes us an awful lot of time and our urban projects are just getting bigger and bigger.

The teachers I asked are telling me that's the only way but I'm convinced it's not. I'm sure there are other more efficient ways to deal with that data. The goal here is to get a 3d model to work on and eventually excell files with height data for each building (I've seen that several years ago in an architecture office but I wasn't very concerned at the time and lost contact since).

So we'd really appreciate any advice/comment/solution you could give on this matter.

Softwares we have access to are autocad, sketchup pro, rhino, 3dsmax, archicad, revit and a few others I can't remember right now.

Sorry for all the english mistakes I may have made :/
and Thank you