archjake
2009-05-27, 12:04 AM
Don't have too much time to post this so this post is a bit scattered and in pieces but I feel that we should discuss some of the problems with the software with regard to virtual construction matching real life construction.
I have a nice little project that we may be doing a hands on design-build. As of such I'm trying to create a Revit model that is dead on with regard to how a building is constructed so it can be utilized throughout the bid and construction process. As it stands Revit really isn't up to the challenge. At the moment the largest problems lie with how walls interact with the structure. Without modeling every separate layer of a wall one obvious problem is that they do not know how to interact together properly.
Example: I have a roof set as a rafter type. I have it set to sit on a level. I also have a wall that terminates at that level. The Roof knows that the rafter should have a "birds mouth" and sit on top of the wall. Well where does that birds mouth start for a bearing condition? Revit thinks it starts with the interior finish layer (the most inner face of the wall) which is set outside the core boundary for the wall. Because of this the roof does not model correctly.
Other problems persist at a roofs rake condition. Only the plywood and roofing material should extend past the wall, out to the fascia board. This makes detailing interesting if we try to utilize the model for the majority of detailing.
Extending layers of the wall gets tricky as well. If a ceiling is modeled exactly I have been able to get the inner finish to terminate at that ceiling by attaching the wall to it. Most of the time it does not work correctly.
Setting up a beam system is a pretty slick tool to lay out roof framing but shouldn't we be able to modify how the ends are cut, or have the roof show framing members of the beam system (with ends cut correctly) automatically?
Other interesting items of note is that a section cut longitudinally through a sloping roof presents a roof thickness which is thicker than the actual components. Yes I know this is how a vertical cut through a sloped item truly gets represented but how does that fit in with our detail components and documenting 2D drawings. I don't quite know if this would be considered more correct or a problem. It just gives an interesting dilemma in documentation. In the past I would turn off the view of the model and recreate the detail w/ detail components but it seems that the strength of BIM is that we should have the model as close to reality as possible and then only add as little as required.
I'm sure my next problem will be the sloping slab w/ a curb and footing as I've run into this in the past.
What are others thoughts or comments? :|
I have a nice little project that we may be doing a hands on design-build. As of such I'm trying to create a Revit model that is dead on with regard to how a building is constructed so it can be utilized throughout the bid and construction process. As it stands Revit really isn't up to the challenge. At the moment the largest problems lie with how walls interact with the structure. Without modeling every separate layer of a wall one obvious problem is that they do not know how to interact together properly.
Example: I have a roof set as a rafter type. I have it set to sit on a level. I also have a wall that terminates at that level. The Roof knows that the rafter should have a "birds mouth" and sit on top of the wall. Well where does that birds mouth start for a bearing condition? Revit thinks it starts with the interior finish layer (the most inner face of the wall) which is set outside the core boundary for the wall. Because of this the roof does not model correctly.
Other problems persist at a roofs rake condition. Only the plywood and roofing material should extend past the wall, out to the fascia board. This makes detailing interesting if we try to utilize the model for the majority of detailing.
Extending layers of the wall gets tricky as well. If a ceiling is modeled exactly I have been able to get the inner finish to terminate at that ceiling by attaching the wall to it. Most of the time it does not work correctly.
Setting up a beam system is a pretty slick tool to lay out roof framing but shouldn't we be able to modify how the ends are cut, or have the roof show framing members of the beam system (with ends cut correctly) automatically?
Other interesting items of note is that a section cut longitudinally through a sloping roof presents a roof thickness which is thicker than the actual components. Yes I know this is how a vertical cut through a sloped item truly gets represented but how does that fit in with our detail components and documenting 2D drawings. I don't quite know if this would be considered more correct or a problem. It just gives an interesting dilemma in documentation. In the past I would turn off the view of the model and recreate the detail w/ detail components but it seems that the strength of BIM is that we should have the model as close to reality as possible and then only add as little as required.
I'm sure my next problem will be the sloping slab w/ a curb and footing as I've run into this in the past.
What are others thoughts or comments? :|