Here is the timings, you can see 480ms frame time while placing objects, but no obvious problem:

The issue comes and goes, sometimes placing items is completely fine, others it lags like this, and worse when the factory is bigger.
Some more details:
i7, 16GB RAM, nVidia 970, Win 7 x64, SSD HD, dual screen (game: 1920x1080, other: 1920x1200), no other performance problems on my computer.