Revit Structure 2013
Footing Elevations in Foundation Tags T ➲
op of footing elevations are commonly found on a structural foundation plan, and many structural engineers like to show the top of footing elevations within their footing tag. Footing tags that are a home to many pieces of information offer a concise way to provide a range of information in one location. The only downside to this approach is that a straightforward method to include the top of footing elevation in a foundation tag does not currently exist out of the box. This article outlines a method to provide a top of footing elevation in a foundation tag.
OUT-OF-THE-BOX OPTIONS Out of the box, there are two options for showing footing elevations. The first option is to simply use the elevation at the bottom of the footing. This instance parameter is available in all out-ofthe-box footings, and a tag referencing this parameter is also available. The argument in favor of this approach is that everything is available out of the box, and little to no effort is required to use this tag. The negative aspect of this option is that a structural engineer would have to change the tried-and-true way he has shown footing elevations on his drawings, as well as slightly altering the information provided on the plan—showing bottom, instead of top, of footing elevations. This option is shown in Figure 1.
PRODUCT FOCUS
by: Desirée Mackey
A positive for this approach is that drawings can continue to look the way they always have, and all of the same information continues to be available in the same location. The negative is that the footing tag is now two pieces and as a result, moving the tags around on the plan can leave orphaned spot elevations. Chasing these around can be a bother and misplaced elevations are easily overlooked, so plans may eventually get to the contractor with stray footing elevations. One might argue that this is not a major concern since design intent is not compromised; however, why not avoid the forthcoming request for information (RFI) to clarify footing elevations?
A DIFFERENT APPROACH Many seasoned Revit users, this author included, would argue to first utilize out-of-the-box options before creating something custom. Even if the out-of-the-box option forces a change in how drawings look or how they are presented, if the information is greatly the same, or at least conveys the same design intent, why spend the added time to go about it differently? Function over fashion, in a manner of speaking. With that said, the following outlines a custom workaround that will allow top of footing elevations to be included in a footing tag.
STEP ONE: CREATE A SHARED PARAMETER
Figure 1: Out-of-the-box foundation tag with elevation at the bottom.
The second out-of-the-box option is to use a spot elevation to show the top of footing elevation. This information may be shown separately from that shown in the footing tag; however, in an effort to keep consistent the look of their drawings both pre- and post-Revit use, structural engineers have tended toward placing the spot elevation next to or below the footing tag. If a company uses a footing tag that has lines or boxes around each piece of information, there is a blank location on top of which the spot elevation is placed. May 2012
The first step is to create a shared parameter for the top of footing elevation that will appear in the foundation tag. This should be a length parameter. This parameter then should be added as a project parameter and applied to structural foundations. There are two reasons to use a project parameter here: First, using a project parameter will avoid the need to edit all of the structural foundation families (and re-editing them if updates occur) and second, elevations of elements are not available until they are inserted into a project, so there is little benefit to putting an elevation parameter into a family.
www.augiworld.com
69