get from https://stackoverflow.com/questions/8440/visual-studio-optimizations#8473
The standard setup for .NET solutions is that each assembly gets its own bin directory to which it is copied along with the assemblies of all its dependencies. If your solution contains an .EXE file and, say, 40 different assemblies. Does it really make sense to copy the dependencies of each assembly to each separate build directory? The target directory of the EXE should be enough. Another way to accomplish roughly the same would be to give the assemblies common output directories. That also avoids the copying. Some earlier versions of Visual Studio did not support this well, so be careful. I have, however, been using this approach with VS2008 for quite a while without noticing any problems.
question - how to disable creating "bin" etc for all child projects? Thanks