When faced with only a small amount of space, a model railroader will usually opt for building a smaller n scale or z scale layout. Another option is to incorporate a shelf layout into the design. This can be in addition to the traditional ‘oval’ or 'continuous run' layout, or instead of the typical train set loop type layout.
Since shelf layouts typically occupy less space they can present some problems for the modeler. A shelf layout can limit the possibilities of incorporating continuous run and track loops. Trains can’t usually be left to run in the same way they can on a loop layout. A shelf layout generally requires a more "hands-on" operation which will appeal to many in the hobby.
Shelf layout operation usually means individual train movements are completed relatively quickly. Operation on a shelf layout is much more intense when compared to operation on a basic loop layout.
A shelf layout is certainly an option worth considering during the planning stages especially if space is limited.