Friday, March 23, 2012

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.

Wednesday, March 21, 2012

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.

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 from the Files and Families tab above .

Tuesday, March 20, 2012

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.

Sunday, March 18, 2012

Using CAD with Revit

There are a few best practices for using CAD with Revit that everyone should observe. When working with CAD keep in mind the simple fact that most CAD files contain layers of information that we do not need in our models.

For files to be used as reference for modeling, always clean up the file in CAD before importing into Revit. Keep only the information that is needed for the model; discard everything else.

Always use Link CAD  (not Import) for files that are used as temporary reference for modeling.

Always use ‘Current view only’ when linking or importing.

If you wish to use the same imported data in more than one view, use Copy/Pastedo not import another instance.

CAD files may also be imported, exploded, and converted into Revit details or 2D symbols.

After exploding, all lines must be converted to native Revit line styles. Use ‘Convert Lines’ to change 3D model lines to 2D symbolic lines.

To avoid loading up your project with useless data that still must be managed, always do this work in a separate project file. Copy/paste or load the finished work into your Revit project file.

Friday, March 16, 2012

What About Revit?

In preparing material for this blog I rediscovered this 'manifesto' from the recent past...
(Scroll to the end for the date).

Building Information Modeling for TCF

Architects have relied upon drawings to mediate design and construction since the earliest organized buildings. The abstract language of plan, section, elevation and detail has evolved into a consistent, global standard for conveying design intent to engineers, builders, and owners. So why change now?

However comfortable they may be, the current processes are beginning to prove inadequate in the face of the increasing complexity of projects. Although architects, designers, and consultants have been using computer aided methods for nearly twenty years, the building construction industry still has not realized the productivity benefits experienced by other enterprises that have adopted automated design and production. A recent study by the National Institute of Standards and Technology reported that the lack of integration among the various components of the construction industry costs the United States capital facility industry $15.8 billion per year. 

Revit is more than a modeling program; it is a parametric building information modeling system, the next generation of CAD software. This new tool serves the entire process from design and documentation through procurement, construction and building operation and maintenance. The parametric building modeling technology upon which Revit is built eliminates the most common sources of errors by maintaining a fully-coordinated representation of the building at all times, while accessing that information through the language of plan, section and elevation. 

Revit was designed to overcome the shortcomings inherent in the standard two-dimensional CAD construction project documentation process. In the Autodesk Revit building model, every drawing sheet, every 2D and 3D view, and every schedule is a direct presentation of information from the same underlying building database.

Some of the benefits of this system include: 

  • Three-dimensional building modeling for design visualization, rendering and walk-through animation. Models may be exported to other programs for high-end, photo-realistic, imaging. 
  • Plan, section, and elevation drawings are automatically generated from the building information model. In Revit, it is impossible for the various drawings in a construction document set to not be in agreement. 
  • Changed information is instantaneously and automatically updated throughout the building model and construction documents. 
  • Annotations, dimensions, and text use True-type, not vector, fonts, and are automatically re-sized if the scale of a drawing is changed. 
  • The location of sections, elevations, and details is automatically referenced and automatically updated when drawing and sheet numbers change. 
  • Door, window, and finish schedules are automatically generated from model data. Changes made in schedules are reflected in the construction drawings. 
  • Revit is extremely accurate. Building components are defined by their actual dimensions. Construction of a building model in Revit allows the resolution of conditions and conflicts which otherwise would not be discovered until they are encountered during construction. 
  • Model data may be exported through ODBC for use with cost-estimating and construction management programs. 
Our Conclusions

The impact of modern technology has finally reached the building construction industry. With better planning, construction predictability will increase while cost and cycle time will decrease. Companies that perform additional planning will benefit from additional fees and reduced risk. Ultimately, the economic beneficiary of better planning is the building owner.

As building owners demand more efficiency and better integration of information, AEC businesses must adapt or find themselves facing obsolescence.

With each successive project for TCF, we expect to add more capability to our building information models, and more value to the services we provide to our client.

A. Jay Holland
Little Diversified Architectural Consulting

January 9, 2006

Thursday, March 15, 2012

Generic Annotation Keynotes

There are three types of Keynoting built into Revit:
  • Element keynotes extract and report data from the ‘Keynote’ field in an object’s type properties.
  • Material keynotes report the value of the Keynote field on the Identity tab of the Materials dialog. 
  • User keynotes allow the selection of notes from a predefined list

Many users find these systems to be too restrictive and cumbersome for the kind of keynoting that is used in day-to-day architectural practice. Drawing keynotes typically combine information about materials, assemblies, finishes or even the relationship between different building components. For these types of notes, the one method that predates all three current systems is the use of Generic Annotations and Note Blocks.

A generic annotation is merely a symbol with associated text fields. The symbol object contains a label assigned to the ‘Number’ parameter. These symbols do not extract data from the model, and so they are often called ‘dumb’ keynotes. Essentially this is the same method used in CAD, with the enhancement of Revit’s parametric capability.

Generic Annotation Keynotes require only three fields:
       Type Name, Number, Description.

Number and Description are the fields that will be displayed on the drawings and in note blocks. I recommend using a keyword or acronym for the Type Name field, to aid in identification. This method allows for easy re-numbering when notes are inserted or deleted from the list. No need for notes that say, “Not Used”.

Generic annotation note blocks can be managed externally using a text file or spreadsheet to create a Family Type catalog. The method for creating and updating Keynote Schedules is described in the procedure guide I've posted on Google Docs. 
Minor revisions may be made in the project, but be aware there is no link to the text file. The best practice would be to keep the spreadsheet up to date and always “refresh” the note list by re-importing the data. Because the type name is not the keynote number, the list can be easily re-ordered in the external text file and re-imported to update both schedule and symbols.

Go to the "Files and Families" tab above to download the guide and sample family. 

We've Always Done It This Way!

AutoCAD Version 1.0 was released in 1982. It was one of several desktop 'CADD' applications to evolve from the earlier mainframe and minicomputer CAD systems. See Marian Bozdoc's detailed history of CAD.

In the days of the IBM PC-AT, it was a very common practice to purchase a single copy of the software, to be installed on several computers. AutoCAD became the "defacto standard" by virtue of its availability.
Now it's thirty years later and we're approaching the time when the majority of CAD practitioners have never put together a set of documents "by hand". We've always done it this way!

That's not a bad thing. It simply shows how much progress has been made. Over time, the 'best practices' for using CAD evolved into an industry standard and were proliferated throughout the profession.

Many current CAD practitioners may not be aware of how and why these methods evolved, which knowledge is essential when evaluating the need for change. I intend to bring these situations to Light here.

So far I am categorizing these anecdotes as "Strange But True".

Monday, March 12, 2012

South Coast Revit Users Group

The South Coast Revit Users Group is the first and foremost Revit user’s group in Southern California. Initiated by well-known BIM strategist Jim Balding nearly a decade ago, we have about 200 active members who meet every month for Revit-related presentations and networking.

Meetings are held at the offices of LPA, Inc. Free food and beverages are generously provided by several local Autodesk partners.

The history of the group was featured in the premier issue of AUGI-EDGE magazine. I served as organizer and co-chairperson from 2006-2011, and continue as organizer of SCRUG on LinkedIn. [click to join]

Each year around the beginning of April we hold a very special meeting to preview the latest additions and enhancements in Revit Architecture. Coincidentally, our next meeting will be held Thursday, March 29th at 6:30 p.m. Revit Technical Specialist Scott Davis will be our presenter, and this meeting usually attracts the cognoscenti of the O.C. Revit community.

To join the South Coast Revit Users Group and RSVP for this special presentation simply click below.


No Further Delays

After a slight hiatus from the conception of this blog to its inception, we are ready to move forward. The blog will remain public and all information posted here will be non-proprietary.

All the tips and techniques I will share have been developed over several years and in collaboration with a variety of AEC professionals, and are offered for the use and benefit of all. The anecdotes, issues and challenges arising from the transition from CAD to BIM will be familiar to many and interesting to all who are traveling along the same path.

This blog's primary purpose is a broadcast of news and information related to BIM transition at KTGY.

Across all five offices, about one-third of the design and production staff have training and experience using Revit. We have twenty Revit users in Irvine, a few in Oakland and D.C., and the entire staff in Denver is Revit-qualified. About fifty users total.

In the first three months at KTGY I've worked on developing BIM content, standards and methodologies. In Irvine we've initiated two multi-family housing projects,  a retail prototype job, and also created models of the ancillary buildings for yet another low-density housing project.

For all who have not yet had the opportunity to work in BIM I offer this incentive: Working with Revit is fun! All who wish to have more fun at work are invited to join the Revit-lution!