Very difficult question to answer without knowing what exactly the room looks like. A standard bedroom is the farthest thing from being suitable for a model railroad. Doors, windows and closets are often asymmetrical and in the way of anything effective.
Ignore the window space if you can live without it- it can be covered by the back drop. The door to the room can be hinged reversed so it will open into a hall way instead of the room giving you more useable space. The closet is the hardest part- you may not be able to cover it in any kind of way. This leaves you with maybe two walls for use of the railroad and an open area for an isthmus of some kind.
I would go with a two walled layout of a folded dogbone style, using a blank wall and a window wall. The tendency is to cram every available square inch with layout, but this is seldom a good idea in the end. You will need the extra space for people to stand in.
The Dixie D Short Line "Lux Lucet In Tenebris Nihil Igitur Mors Est Ad Nos 2001"
Everyone so far has given you good advice. I personally don't worry about holes in the walls because I know that I can repair them so you never knew they were there in the first place.
I once did a small width layout in a bedroom by using 1x8 boards around the walls hung with shelf brackets. (In N scale) The part across the door and closet was a lift-off section. The track power was connected using plugs. I have also done a lift up bridge, a swing-down bridge, and a swing-gate (like a door), all for N scale track.
The trick when building lift-bridges, swing-gates- or lift-off sections is to build the end parts as stable as you can, then mount the movable part. Next make sure everything is straight and level (or in line) between the two ends and middle, and that the movable part will return to the exact same place at both ends all the time. Once you have that done, then lay the track. Don't use roadbed for three or four inches on either side of the crack, but use something solid like wood shims. I am in the process of building four lift bridges across two doorways. (HO scale) I am using the Woodland Scenics foam roadbed, but at the bridges, I am cutting Luan roadbed to be used as a firm support base for the track as it crosses the gaps/cracks. The Luan just happens to be the same thickness as the foam roadbed. Anyway, for the track crossing the openings, make them into one long section that extends a foot past each gap or crack by soldering the rail joiners. Then lay this piece of track over the bridge and mount it in place. I am using caulking. For the sections that cross the gaps, I am using Super Glue to hold the track down on the Luan, and I am adding spikes to the rails through the ties after drilling very small holes. (I detest track nails). Once this is all dry, then come in with a Dremel tool and a cut-off disk and cut the rails/track at the cracks at each end of the lift bridge so it will open. (Now you should have noticed that when attaching the track, that it will need to be left in place at least over night, so you will need to make any accommodations for this as required in your situation.) Another thing that you can do if you need to, is remove any doors and replace them with curtains. Just keep the doors so you can put them back up when you move.
I am building my current HO layout in 2x7 foot table type modules. Framing is 1x3 furring strips, covered with sheet Luan, and topped with one inch blue builders foam. The modules will remain in the same configuration when moved. They are set on L-girder sections that are screwed to the walls. (My last layout was built using the L-girder and open joist method and I have a lot of the girders left.) Then the module sections are screwed to the girders and have legs on the front side. The first module would usually have two legs. The next module bolted to the first at the end and only needed one leg at the far end.
As far a designing a track plan, I like to find switching module plans in the hobby mags and build them as modules to use for my towns. Most of them tend to get modified to fit what I am building at the time, but it is a great starting point. Then just connect the mainline track between them.
Hope this helps.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
In many cases, a mix of against the walls and island peninsulas works well. There's typically no reason for this to be an "either/or" question.In my humble opinion, it easier if you decide what you want to model first. Sleepy branchline, terminal switcher, mountain-goat-like logger, etc.? From that decision, you can start to get an idea what the space needs to look like: will you need enough benchwork width for loops and turnbacks, or will narrower benchwork suffice for a switching-style layout?Then look at the space available. If you are looking at three or four different rooms simultaneously, it becomes hard to get focused, in my view. One of those rooms is probably more conducive to layout construction and operation than the others. Some factors might be door location, available walls, overall square footage, etc. Narrow your focus to that room first. If it doesn't work out, you can always go back to the drawing board with another room, but at least you'll get started and be out of the "paralysis by analysis" phase.Next you can start sketching roughly, but to-scale. This will give you an idea what really fits and where you might locate main elements. Be sure to leave space for aisles and access.As this process continues, a benchwork shape will begin to suggest itself, whether along-the-walls, island, or (often) some mix. Layout concept and interests will determine track plan, track plan and access will determine benchwork shape, benchwork shape will determine construction method. Not the other way around.Good luck!ByronModel RR Blog
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A couple different considerations, the first being how you support the track (the benchwork/roadbed) and the other is how you support the layout (legs/brackets).
The benchwork world falls into 4 general categories: tabletop (plywood sheet/foam sheet/door ), a grid (open grid/domino/modular systems), L-girder and spline (lath/masonite/homasote). If you want to break it down into small chunks, then L-girder and spline are probably not the way you want to go. You probably want some sort of sectional design with small table top or open grid sections that is fairly portable.
The supports can be legs, brackets, cantilever and suspended. For your purposes, the difference is how many holes you want to put into the wall vs how much floor space you want to intrude on. If you want to minimize holes in the wall at the expense of limiting floor space, you want to go with some sort of legs support. If you want to maximize floor space then you want some sort of bracket system (that will result in some screw holes in the wall.)
If you are limited to legs then you will probably want to go with an open grid system. If you go with legs and a flat section, you will end up building some sort of grid system anyway to connect the legs and support the flat sections. If you are going with brackets, you can go either way, putting flat sections on the brackets or resting the grids on the brackets.
Dave H.
Dave H. Painted side goes up. My website : wnbranch.com
Lift out/swing out gates can be made to work reliably in N scale; it's just a matter of good carpentry.
It would be a good idea to design a layout that grows incrementally. A dog bone layout would be good, with the end loops as modules. You could start with an L shaped layout, then expand to a U shape, then expand to completely around the walls.
Good luck on your planning.