@Mark Boyce posted:Construction space, power tools, storage, and transportation of modules are concerns of mine, since as I told Andy, I have no room for any of that.
Mark, my module, when not in use, is stored in my basement and takes up only 6 inches x 4 ft. of floor space (standing on its back end) plus a little space for the legs. All my scenery is removable and takes up just a little more space.
Transportation is usually the big concern, and modules need to be constructed to take this ability into account. And you also need to be physically able to carry your module or have reliable help in loading/unloading at home. My module is 4 ft. x 4 ft. and will fit in the back of my extended cab pickup with the rear seats folded up. In good weather, I can use the bed of my truck, and in bad weather, we have used plastic wrap (shipping kind, not kitchen kind) to wrap modules for transport in the rain. Others without trucks or vans can often fold down their rear seats to take advantage of trunk or cargo space to transport their modules, so examining and measuring your vehicle is a must before building a module. Modules can also be built in sections -- front section containing tracks & road, and rear add-on section(s) for scenery. There are all kinds of ways around space limitations. In this part of the hobby you learn to be very creative in packing things. 
As for construction and tools, not everyone has all the tools or space necessary, so we usually build our modules as a group project. That way modules go together quickly (we can knock out a module in one evening work session, and could probable do more if enough people are on hand), and multiple sets of eyes can help keep mistakes and problems to an absolute minimum.
Andy
