BIM - Risa and Wood Framed Design

You may have heard talk about Woodworks teaming up with Risa with a view to providing software in exchange for essentially a "glowing report" and feedback etc about the process. I have spent several days on this issue since we decided to model our smallest building on the Ash Way project in Revit. We thought this to be a good chance to further our Revit experience AND to enter the fray of modelling anaylis. These are my findings:

1. Building the model: The idea of building a model once, and using it to perform your analysis and then doing "double duty" and using it in drafting duty is indeed enticing. It is the definition of Nirvana in the BIM circles...
   Unfortunately, Nirvana has not yet arrived! The marraige between Revit and Risa leaves a LOT to be desired. Having used Revit previously, we can build the model well enough - although there are some new nuances with respect to (wrt) ensuring that the "analytic model" (where the centerlines and workpoints of entities are that an analysis software would use for crunching numbers) is well thought out, and that the nodes connect EXACTLY!
   Revit is able to export its model to RISA through a link. This does effectively transfer info about geometry to RISA, however there is MUCH legwork to do after that.
   It should be mentioned that using RISA - actually using TWO pieces of software - RISA floor and RISA 3D. To try to create "Nirvana" it si necessary to know BOTH these softwares well!
2. Some of my pet peaves with the RISA match up are:

• Material properties are not imported from Revit - you need to set up every wall with correct parameters - once set the parameters do not make it back "into the model in Revit"
• Doorways and Windows are not imported into the RISA model... wth!? you may well ask - i did! The answer is to be found in the small print - you have to model each opening as an "opening in a face" - a Revit term that requires a different process than a window or a door insertion! (did i mention legwork...?)
• Import of DXF files: There is not import of a DWG background. additionally import is very querky into RISA. I finally got a dxf to import - but you ahve to "doctor" the file to import walls - walls need to drawn on a layer with a polyline - where the "gage specified" is the wall thickness - only then will it import walls! - Who knew!
• RISA itself does NOT model flexible diaphragms: The whole point of doing wood framing....! Insted you are left to apply an "area load" which apparently applies loads to walls based on a "pseudo-area" assignment. It was not immediately obvious to me exactly how this was assigned on a complex wall arrangement.
• Re-work of walls: Even though the models were imported form Revit, and did stack, RISA had problems with many of the node points... Leading to re-create nodes in the RISA software... can you say "time consuming...?"
• 2-stage analysis - redefined: RISA wants you to use Risa Floor in order to provide some "pre-processor" capability as a prelude to the RISA 3D work over... The problem with this initial setup is the software wants you to do a "complete" framing plan, and model all aspects of the wood framing BEFORE it will transfer you to RISA 3D - where the heavy lifting is done - the lateral analysis!
3. RISA Output: In theory RISA can provide a good calc and some decent output - see printouts below. However the overhead required seems onerous. It seems that in "our world" where we have 3 or 4 span conditions to design floor joists for - its unreasonable to create a whole model to determine something that we can do by hand in 15 min. Also the wall design fro gravity - again the same comment applies - we have a couple of wall types... it takes 30min to design the studs... do we really have to model every single wall in the project in order to proceed onto the "the juicy bits" ie lateral design. (of course Risa will tell you all you need to do is input dummy elements and sdummy loads etc... all that still takes time, and now you're starting to wonder if these short cuts are going to affect the veracity of the output... ie what is it using in its calcs...? )