Historical city reconstruction workflow I'm doing some historical research and I would like to visualize a situation from the past. 

I have several questions, I would like to make this topic a source for tips &amp; hints when recreating e.g. cities.


I've seen that it is possible to create a surface from Google Earth with Sketchup. Is something similar possible with Blender? I need correct geo. reference and heights.
Via Solid Edge ST6 I can easily use a measurement tool when creating my model. (e.g. https://www.youtube.com/watch?v=GI8QE5A2fWY ) Is something similar available for Blender? 
Some models I need on my map need to have correct sizes.
In general, how do you best organize a large scene?
at the beginning I just want to add basic shapes (e.g. cubes) to show the buildings. If I later want to update these buildings or add more detail to an existing building. What is the best way to work?
You could try to export from OpenStreetMap
How to model effectively using exact measurements?
It depends on what you want to achieve (should be another question) you could use layers and groups.
For buildings in the background adding textures should be sufficient for close up I would refine the geometry and add more materials. Related: Trying to create a script that makes roofs on selected boxes


Imported .osm after extrusion (Note that exporting a whole city leads to 2GB files which can't be loaded in Blender)



For some cities 360° images are available from Google street view / maps view which help to elaborate on building details and estimate their age.



Check this awesome tutorial Blender tutorial: How to Create a City