Jonathan,
The 2,400 Sq-Ft ranch house we bought three years ago had a 2,200 Sq-Ft basement; totally unfinished except it had a nice 5 x 10 full bathroom already done with the inside completely finished. After much deliberation, I decided to divide it thusly:
Train room: 33 x 38. (There is a 9 x 20 area for guests to gather.)
Study: 12 x 22
Shop: 16 x 22
Exercise room: 12 x 12
Utility room: 10 x 12
Bathroom: 5 x 10
Hints (many have been voiced before)
• Make sure the basement is dry. If it is not and is not a question of leaks, dehumidifiers can help – again, if it is just a question of humidity.
• When dividing up the basement, remember that it is very handy to have a workshop close to the train room. Other rooms will come in handy as well, such as a bathroom, study, etc.
• When planning the train room size and layout, keep in mind what your objectives are, and how much time you are willing to wait until the layout is ‘finished’ to a reasonable degree from your point of view.
• Finish everything (studs, wiring, drywall, mudding, painting, ceilings, and flooring) before you start the train; even if it means painting the backdrop or pasting purchased backdrops over the freshly painted train walls.
Good Luck!
Alex