Good afternoon all. I may have the oppertunity to build a new layout after the first of the year as my parents are planning to move to the Dallas TX. area to be closer to the Doctors and not have to worry about all the stairs around here. So it they do move, and it is almost certain they will, I will have this big houst to myself.
In this house is an attic that is about 40 ft. long and 30 ft wide, if I play my cards right I may be ablt to move my layout up stairs. Here is an overview of what I am trying to describe. (Sorry I am no artist.)

The outside walls (the 40’ ones) are only about 4’ tall on the inside and slope upwards to the center of the house, where the ceiling is only about 6 1/2 foot tall. I think this would make a great train room, as I could come up the stairs into the center of the layout and have a huge double or triple continous main line and all the yards and sidings I can build.
I am thinking of this now because I would like to have some kind of a plan befor I begin. I would like to here some suggestions as to making a track plan or just suggestions in general.
Right now my bedroom is up there as well as a couple of smaller bedrooms, All the walls can be removed if needed. At the time this house was built there was one big room up there (no walls) I would like to have a large bridge across the staircase that would make ART Hill green with envy LOL. Any and all suggestions are welcome, I am kind of excited about it all. Thanks a lot. Mike
P.S. the drawing is not to any scale at all
I have a feeling that Attics freeze in winter and fry in the summer. I installed two turbines on my home to get the heat out of there in the summer and extend the life of the roof.
I dont know if your Attic enjoys the same insulation and is supported by the Climate System in your home or not, but you might want to consider extremes in temperature and humidity.
Also consider the volume of material you can get up there by yourself. that will help you consider how to build it.
Did you put down or already have a subfloor because most attics Ive seen are just joists port to starboard with insulation in between making for very dangerous footing because the ceilings below that cannot hold a person.
With 17 feet of usable width, I would consider a center peninsula. The layout could be 2.5 feet wide along the walls with 4 foot wide aisles on either side of a 4 foot wide peninsula. The peninsula could be a stub ended yard that could serve trains traveling in either direction on the continuous mainline. It could be a switching/industrial area or large urban area. It could even hold a branch line off the main. There are a lot of possibilities. It looks like the peninsula would have to stop about 3 feet short of the stairway. And it’s hard to see from you diagram just how long it could be. Another possibility would be to stack reversing loops in the corner nearest the stairs with each loop having multiple staging tracks. This is the arrangement I have in my basement layout which like yours, is a large rectangular area. With reversing loops, your trains could run back and forth between the loops which is more prototypical than running them around and around. The mainline would only have to climb about 6 inches between the loops to allow sufficient clearance. It sounds like you have a great space. You probably want to give some thought to climate and dust control since this is an attic. My old house was a story and a half and until I put in central air, the upstairs was unlivable in the summer time.
Safty valve the attic here is fully insulated and sheetrocked and has a full wood floor, as I said there are bedrooms there. It dous however get quith hot in the summer and I have a large AC I have installed in the south wall which keeps it quite comfortable in the summer and in the winter it doesne cet all that cold as the floor between the middle room and the upstairs is not insulated. If it gets really cold I can warm it with a small gas heater whigh there are several gas outlets already there.
Also I forgot there is a 18’’ chiminy in the center of the attic. When we were young All of us kids (4 of us ) had our bedrooms there. Mike
That pretty much settles the attic space to run trains.
Now another is electrical. Do you have sufficent electrical service to the attic to do everything safely?
The electricty up there has not been redone since 1964 when the house was remodeled. The main wiring from the pole to the house is on the outside on the north, wouldn’t be hard to add a padel box there, the wires for the mast part can be run in the cubby holes as they are not finished outside. This is something that needs to be done any way whether or not I make it a train room. Mike
draw it to scale , i think you’ll find you have more room than you think you do