Some excellent and helpful replies above.
My layout is based on a real location in 1970s North East England, a loco depot and coal export facility and will be known to people familiar with the area, having said, because of compression, the upper and lower sidings are not long enough nor is there the correct amount of sidings, the buildings on my layout are not totally accurate and some of the other trackwork work is inaccurate but I am happy with my layout being an 'interpretation of' or 'loosely based' layout.
There is nothing I can do but work with the space I have and try to get my layout as close as I possibly can with what modelling skills I have and I use the word skills very loosely!
I say go for it but most of all enjoy your modelling.