Inspiration.

Allan Downes, years ago produced some articles for the model railway press. One of these that sticks in my mind is one entitled 'One Barn thing after another'.
Three booklets were produced, two of which are extremely useful for those needing some ideas for buildings. These two deal with the non-railway infrastucture and, whilst scaled for 4mm are easily scaled down by the formula divide by four and multiply by three giving correct 3mm size.
Whilst not adhering faithfully to the plans, basic sizes and spaces given save an awful lot of time.
So out with the card, ruler, knife and brick paper!