first side of the factory building I'm currently constructing took a full weekends worth of modelling, the other end, although more complex, came together much quicker. Once you get the hang of how sections are constructed the repetition is actually quite helpful.
I did manage to catch the bottom of the brick work with the modelling knife which was a bit of a shame, but I've covered over the mark with a brown felt-tip pen to hide the worst of the damage. When I bed the model into the surface of the layout (so it doesn't appear to hover), I'll find something to hide the damage behind; probably a clump of weeds or something. Anyway I wouldn't want the factory to look pristine so a little bit of wear and tear is fine. Given that it's supposed to be a dark satanic mill I'll need to add some soot over the whole thing anyway which will hopefully help to hide any small blemishes.