I was just working on a project that had a room sized steel tube component that I started out modeling as a 3/4" steel wall type, but quickly abandoned that approach when I realized how crappy curved walls are in revit (split into quadrants, can't edit the profile, openings are shifty)

I ended up modeling a custom family of the whole assembly and dropping it in the project, curved extrusions are so much cleaner to work with than curved walls.  

I am not familiar with any of the conceptual massing tools in revit, I typically try to build everything out of the tools available in the software (floors, walls, ceilings, structural framing, beams and columns), but setting up each so it matches the exact configuration of what you are proposing to use in reality, 3/4" thick floors, 1/2" thick walls, stuff like that...just building the architecture piece by piece.  

I also have two families that I use all the time, they are sweep/profile based instance families, one vertical, one horizontal that I can drop into a project and stretch to any length or height and easily modify the profile to whatever I want, so if I need a 2" angle steel, I just change the profile in the family and re-save/import and go.  I find these much easier to use than the over-constrained built-in structural elements (beams/columns) with all of these locked top/bottom constraints, they really suck to work with.  

I know this is a big no-no, but I also use in-place families from time to time, just for ease of placing on a specific work plane in the model...it is so much easier than trying to configure an external family.  

The thing I have found with revit is this:  it is very easy when you are just using out of the box tools, rails, stairs, walls...but the kind of architecture you want to model will not be able to be automated.  That being said, I have found it better to model super custom things piece by piece, like rails, and making custom families of stairs/stair rails, etc. 

What the developers really need to come up with is an in-place family editor, that saves the family that you modeled in the project to an external family file...I find it so stupid that you have to record a bunch of dimensions out of your project/model, only to open an external family file replicate all of those dimensions....it is just a dumb workflow.

You will also have to be creative with the walls on the roof of that project...can't really create a sloped wall in revit, without some hack work-arounds, just search youtube for sloped revit walls.  

Just think about it how you would build it, piece by piece and don't rely on the automated systems too much, you will spend tons of time trying to configure some handrail that you could just model faster than messing with the build in rail editor.
 

My 2 cents.  

Thank you for your input, much appreciated. The sweep based families is a really good idea that I didn't think about. I thought of the adaptive component in the massing tool, which is fine but as you said, going back and forth from massing environment to project environment is not particularly pleasant.

Well, I'm going to try out some of your suggestions and see how it goes.

"What the developers really need to come up with is an in-place family editor"

That exists.

If it's custom and in-situ, then saving it out of the project is unnecessary. If it needs to be reused, then it should be modeled in its own family with parameters used to control the aspects that need to relate to the architecture around it when placed into different circumstances.

See below:

read the post pete...I already said I use in-place families, I think they would be more useful if you had the ability to save the in-place families to an external family file after creation.

I read your post. I addressed your desire. Tool for the job.

"If it's custom and in-situ, then saving it out of the project is unnecessary. If it needs to be reused, then it should be modeled in its own family with parameters used to control the aspects that need to relate to the architecture around it when placed into different circumstances."

You shouldn't need to go back and forth between environments. If it's truly custom there's scant need to export it to a family.

Thank you SneakyPete,

 I knew the in-place mass option but I didn't know you could even place adaptive components into it. Seems like a good option for what I want to do since I won't be reusing the pieces in other projects and I don't really need to assign parameters. I learned a few tricks from this thread and my little project is already going well.

Thanks

Sorry if I came off prickly. If you need further help, please come back and let us know.

No problem Pete,

 Maybe my question lacked clarity. I went through some tutorials that used only project environment tools and some other that were using only conceptual mass. The tutorials with project-only tools are often really simple and the tutorials on conceptual mass often deal with overcomplicated stuff or early phase brainstorming. My question was more about efficiency of workflow for highly customized projects, creation of family vs mass vs in-place mass, automatic tools like railing or stairs, and what is generally used. 

I'll work more on my project during the weekend and keep updated if I encounter problems.

BTW, I found on a blog that it's possible to save an in-place mass as a .rfa file.