Family Naming Simplified

Revit is an open system - the naming of files and family components is completely up to the user. Practice has shown there is much to be gained by adopting a naming convention or guideline. 



In Revit Architecture there are 21 external family categories, whose purpose includes the behavior of components including visibility, line weights, etc.

Assigning a keyword to each category facilitates sorting and results in grouping of content of similar categories within the pull-down menus.

Hosted objects

For most objects the default host is assumed or apparent. A ‘location’ keyword is useful when the method of hosting is variable or not the default: (CB) ceiling based; (FB) face based; (FLB) floor based; (LB) line based; (RB) roof based; (WB) wall based.

When naming external families, it's a good practice to proceed from general to specific. Sub-categories to be considered include Type, Description, Use, and Manufacturer. Use the suffix ‘2D’ to indicate families composed of symbolic linework or detail components. Otherwise assume the family is modeled 3D geometry.

Examples:

GEN_WB_Sign-Oval-36
PRO_Tile-SpanRake-Base
WDO_Multi-Panel Recessed
SPEQ-FB_Seat Cover Tissue Dispenser- Surface Mtd - Bobrick B-3479
SPEQ_Grab Bar-2D

Slab Depression - Part 3

Revit facilitates an iterative process in which the output is constantly being improved. For many Revit is the antithesis to CAD, where, due to the complexity of the system, the goal of quality is often perceived to be an effect of consistency, which is pursued through standardization.

With Revit quality is seen to be an effect of innovation, within a modular system that supports and facilitates innovation. Once every year a new version brings new tools and functionality, to be implemented as needed, but in practice the improvements are incremental and continuous.

Soon after I deployed the Slab Depression families I received a request to slope the depressed surface to enable tagging with spot slopes. It was a fairly easy task to enhance the original void extrusion with a blend tapering from the outer boundary to a three inch square bottom surface representing the drain location. 


The depth of the depression, however, had to be set manually in order to achieve the desired slope, more or less by trial and error. 
The required depth for any slope is determined by the longest distance from the perimeter to the drain. 
An Internet search on "Revit conditional formula" led to this discovery on Autodesk WikiHelp:


if(A > D, if(A > C, if(A > B, A, B), if(B > C, B, C)), if(B > D, if(B > C, B, C), if(A > D, if(A > C, if(A > B, A, B), if(B > C, B, C)), if(B > D, if(B > C, B, C), if(C > D, C, D)))))


This is a conditional formula which by comparison returns the largest of four different values  originally posted  by 'ekkonap', a Revit user in the Netherlands, on www.revitforum.org.

The formula variables were equated to the four distances, and the depth calculated as a percentage (0.25/12). This slope factor could also assigned to a parameter.

The faces of the depression may be painted with floor materials, or for simplicity a level floor may be placed into the recess. As a serendipitous effect of this modeling strategy, the slope lines are now edges which can be transformed to hidden lines with the linework tool. 


Go to the Files and Families tab above to download "GEN_Slab Depression w Slope.zip

Spanish Rake Tile Families

Work on the mission style project led to further development of the families posted earlier this month.

The design drawings depict a Spanish rake treatment on the gabled ends of the building. As seen in the photo below, the exterior finish is warped (over a foam filler) to the bottom edge of each rake tile.

Similar to the tile families, the filler is a face-based generic model. When placed it may be aligned with the roof and tiles with line modification commands.

When considering how to achieve this in model form, it became apparent that the previous families would have to be modified. New families have been posted in which the tiles are larger in diameter and length, and also closer to the roof surface. 

This modification also mandated a change in the method used to correct the rotation when the opposite face is selected as host. A conditional formula combined with a yes/no parameter is now used to reverse the orientation of nested tile families.

Go to the Files and Families tab to download.

Ridge & Rake Tile Families

Line Based Tile Families -
When using Revit on small scale residential or commercial buildings, while we do not model individual roofing tiles, a more realistic appearance can be achieved by adding ridge, rake, and hip tiles to the model.

These families are derived from some very familiar ones which have been around for several years, their origin now obscure. The individual tiles are created using the geometry 'swept blend' with external profile families. This choice allows the profiles to be mirrored parametrically.
The tiles are nested into a line-based generic family and arrayed with constraints to the beginning and end. The tile spacing is variable 


I modeled a Revit roof for each roof pitch that we normally encounter, then used sections and detail views to determine the appropriate angle for each hip and ridge type.

Families are placed by drawing on a selected roof face, or by selecting a roof edge using the 'pick line' tool. (In some cases the families install opposite of the intended direction with this method.)

As the line-based family may be hosted to either face, a yes/no parameter is included to reverse the profile.


The roof tile material may be assigned in Object Styles > Generic Models > Roofing Tile.


With line based families, the Trim, extend and align tools are active and facilitate placement, as depicted in this short video...

The families may be downloaded from the 'Files and Families' tab above.

Symbols in Keynote Lists - Strange but True

Among the drawing efficiency improvements that were introduced in the Systems Drafting era was the concept of  "Keyed Notes". 


This technique evolved from the desire to standardize and streamline repetitive notation. Symbols on the plan replaced the hand-lettered notation, resulting in clean drawings and efficiency in making changes.


Eventually the numbered lists were produced by copying a type written master onto adhesive backed transparent mylar. The typewriter did not draw a circle around the number, nor did we.


Fast forward to CAD. The keynote symbol is an attributed block and it is so cool because I can double-click on the object and edit its contents. Since all the notes are placed as separate objects, or perhaps as multi-line text, it's easy to copy the same block vertically to create the numbered list.


Revit was designed to solve the deficiencies of CAD. In this case it is the link between the numbered list and the symbols on the drawings. In (vanilla) CAD there is none.

Neither software can automatically place the symbol in the numbered list. Only Revit can update the list automatically, transparently, in both directions.


It is a widely accepted convention that a legend should be included to explain the different types of symbols used in a set of construction drawings. The keynote symbol should be included in this legend, and if it is there is no need to repeat the same information in a note list.

Slab Depression - Part 2

I stated that using Revit leads to expansive thinking. Often when I re-visit a recently-constructed family I add to it, enhance it or improve it in some way. When I began the previous post the drain annotation was not nested with equality constraints. That was an on-the-spot improvement. This is another example.

For the same project I also needed an L-shaped slab depression. Starting with the previous family, I added a second reference plane in each direction, and created additional instance parameters for each.

I added the slope lines and constrained their end points to the planes. That was fine as long as the floor drain was placed separately, but I realized that automatically locating it at the intersection of the slope lines was a challenge. 


After some deliberation, it occurred to me that the drain location could be established parametrically, and if the slope lines could be constrained to the corners of the object, I might also be able to lock them to the drain annotation object. This was accomplished by placing two grouped reference lines and constraining the slope line end-points to their intersection. 



New 'Offset' instance parameters were established to control the location. The drain annotation was aligned and locked to the reference lines.




I assigned the slope lines to a new subcategory 'Slab Depression Slope Lines' to allow view-specific visibility control.







When the object is highlighted in the model triangular grips appear for all parameters. I have also revised the original rectangular slab depression, incorporating these improvements.



Revit is expansive. 
For all three families download GEN_Slab-Depression.zip from the Files and Families tab above .

Quick Slab Depression

I'm working on a building that has several areas where the concrete floor slab must be depressed for ceramic tile finish and sloped for drainage. It would be easy to place a couple of hidden lines on the floor plan, drop in a 2D floor drain, and be done with it. That's what I did on the first pass. I soon realized that the slab depressions would also need to be shown on several other drawings: Slab Plan, Export Plan, Enlarged Plan, etc.

The general guideline for Revit is that if an object or feature appears in more than one view...

Model it!

I created a floor-based generic model containing a void extrusion with instance parameters to control the length, width and depth. I used symbolic lines for the hidden "slope to drain" lines as I prefer them to appear in plan only. I copied the generic annotation from the Floor Drain family and used equality constraints to locate it in the center of the family. Yes/no visibility parameters (Show Drain; Show Lines) allow the appearance of these to be controlled in the model.

As with all basic Revit families, this is just a starting point. The possibility for further development is apparent. 

• Multiple floor drains. 
• Sloped slab using a void blend below the extrusion.

Download 'GEN_Slab Depression.rfa from the Files and Families tab above.

~

Like architecture, great software doesn't just happen, it is designed. 

Revit is designed to be expansive. Operations are consistent, logical and intuitive. Learning is incremental and the curve is steep - which means users achieve high productivity in a relatively short time.