Kit of Parts

Architects assemble buildings from individual parts in Revit. Pre-set elements are part of templates and libraries for easy access. Any building starts from a kit of parts, just like the furniture from IKEA. A ready library of walls, floors, roofs, windows, doors, stairs, components, annotations, and formats can be customized to whatever you want for the design and documentation of architecture in the Revit Building Information Model environment. You can set it up as you please.

Best Practice

Is there a best way to approach to creating a uniform set of building blocks in Revit? Standards sometimes exist for standards’ sake and are not worth having unless they make things better. A good Revit standard keeps work clean and understandable, with fewer unnecessary steps or distracting choices; no need to “reinvent the wheel” every time. On the other hand, over-defined standards can become overwhelming, reducing speed and flexibility. The value of setting elements up before hand goes away if the Revit user is tempted to abandon the system and make what they need ad-hoc.

Building the Library from Generic to Realistic

A kit of parts that works in Revit starts with generic components and extends to the more complex. No need to force detailed decisions early. Provide a basic spectrum of choices systematically named so the designer can find them. Show only to the level of detail that is needed to communicate clearly, which is no different that in the days of hand drafting. Just because we can show high level of detail in Revit doesn't mean we should. Don’t weigh the process down.

Look it Up

One of the most important aspects of a good library is to clearly codify the choices. A graduated series of standard components can be given short, logical, findable names. Keep the library small, containing just the parts that serve as “seeds” for duplicating to similar types parametricly.
Human memory is limited, but we can always look it up, or make it as we need it according to a system.  Standards should extend to the text, tagging and formatting of the model in all phases, from schematic through construction documents. Good standards streamline and help us visualize and communicate the work, The same model serves as the basis for clear diagrams and stunning presentations as well as highly technical documentation, with format styles already built in. In Revit, it is best to set it all up right from the start, with an effective kit of parts.

The Justification for Alignment

Architects love to align things,... professionally.   Original typesetting involved “justifing” text to “make it perfect” by aligning left and right margins, now anything that can be aligned uses this sense of the word.  Architects take a keen interest in this subject and Revit parametric models make it easy.  A prime example is how architects work with walls.  We assign a plane of alignment to a Revit object that helps quickly, precisely control how they are placed as we compose in plan.  (See the previous post, Dimensions - the Nominal,  the Actual, and the Usable,  for a “prequel” on Revit dimensioning).

Exterior Face, Interior Face, or Centerline

A building, unlike justified letter type, is in three dimensions.  Walls in Revit have a defined, flexibly 

placed justification plane, or “location line”. The easiest way to establish and use this is in a “flat” view - a plan, elevation, or section.  The location line refers to some aspect of the exterior face, interior face, or centerline.  In a typical case, the exterior wall location line is set to finished exterior face, say the  face of a brick masonry faced wall; The justification for a gyp board stud wall partition is frequently set to face of the supporting stud. the “core” of the wall.  In early planning, justifying to the centerline may prove easiest to control, allowing rapid experimentation and adjustment as spaces and rooms divisions are made in resolving program and room configuration.

Eyeballing vs. Nailing It in Schematic Design

Portion of a Schematic Design Plan View for a School

Defining that much may seem over-precise. Why not just “eyeball” (visually estimate the measure) the geometry loosely, at least in the beginning?. But nailing spacing to a precise dimension early actually helps keep design efficient from beginning to end in Revit.  At first, materials may not be easy to define and dimensions not known.  That doesn’t matter; use a placeholder.  A generic 12” or 16” exterior wall works to start.  A Generic 5” interior partition will do the job as ideas are forming, and can be swapped out later. Eventually, it may be 4 ⅞” or 5 ¼” , 7 ⅝”, or any of a number of other possibilities.  That level of detail can safely come later.  The designer can lay strings of working parametric dimensions to quickly adjust and control spacing, keeping geometry simple and understandable with walls alignment to a consistent location line.  Wall widths can flex as refinements are made without changing the basic dimension system.  Controlled adjustments can be made by simply “nudging” walls with the cursor, or changing the “live” working dimensions.  Room area tags can give feedback on resulting areas until a target is reached.  The model can be both precise and flexible.

Portion of a Construction Drawing Plan View for a School

Declaring Peace in the Dimensional War
Depending on your priorities as a designer or planner, the most important surface in a room will either be to the face of the underlying structure or to the face of the finish that is applied to it.  Architects seem to take sides on this when it comes to dimensioning methods.  The first thing placed in construction is the structure, in the case of a partition, the stud.  Place it to finish, and you force the framer to do the math on the fly as they subtract intended finish dimension to determine where to mark for the stud location.  Easy to make mistakes.  On the other hand, when detailing the precise placement of elements in a room, such as a counter or an opening, the designer wants to track the final appearance and fit, not the underlying structure.  Thus, the primary dimensions should be to the finish face, instead, right?  Revit’s versatility makes this conflict mute. The dimension can be placed to core, while the wall graphic still displays the actual dimensional position of the face layer.  The model scales in the true clear dimension to assure design fit while plan dimensions are to the core, the way it is constructed.  Design and documentation geometry can finally work together. Different plan and detail views can be created of the same model to meet the needs of the various team players.   

Perspective View of School Corridor Design

Revit enables collaboration and integration.  No need for the thinking of schematic design, interior design, and construction documentation thinking to stay isolated in silos.  One of the most important outcomes of using a model interactively like this is to allow us to form and describe the architecture with an eye to the final outcome, coherent and useful space.  A peaceful outcome.

Dimensions - the Nominal, the Actual, and the Useable

“Order is the balanced adjustment of the details of the work separately, and, as to the whole, the arrangement of the proportion with the view to the symmetrical result.  This is made of the Dimension, which in Greek, is called posotes.  Now Dimensions is the taking of modules from the parts of the work: the suitable effect of the whole work arising from several subdivisions of the parts.” - Vitruvius, 1st century BC.

Dimensions are at the heart of Architecture, running through from initial conception to final detailed completion.  They are an essential system that runs through design thinking.  Architects are obsessed with them, and there is no end in the debate on how they are best used. Revit, a tool for parametric modeling, offers interesting ways for Architects to resolve dimensions in design.  But the tool is only as good as the thinking behind it.

Nominal vs. Actual

Shorthand for measurements abound in and around buildings: 2x4 stud, 8 inch brick, 8 foot ceiling, 10’ x 12’ room,  20 foot span. , These are not exacting, but offer a nominal size that we can easily get our minds around.  The cross section of a wood 2x4 rough cut board is actually 1 ½” x 3 ½” , plus or minus ⅛” (at least in my part of the world).  The 2” and 4” are nominal dimensions.   Architects obsess over dimensions in different ways.  In early  design, arguably,  nominal dimensions provide simplicity for the big picture, but certainly introduce problems.  Some special cases for rounding can be made, for example an indication of a room size to a client early in design, could be to the inch, or even the foot. 

I have reluctantly defined these special, grossly rounded dimension styles at times.  In a recent project, I found found them used in place of exacting dimensions. After that, I thought of banning rounding, but instead defined the style to shout out in a loud color limit their use and eventually flush them out. Nominal dimensions in a design fool us into sweeping issues under the carpet that will be faced again in the design of a building.  Critical dimensions must be precise: An elevator may not fit in the shaft required.  A corridor may too narrow to serve as an emergency egress. Trades may not be able to coordinate any number of construction tasks, given vague dimensions. But these vague, nominal dimensions may be useful to unclutter thinking in earlier stages of design….or are they?

Actual dimensions, accepting small fractions of an inch, can get complicated fast, but are the only option in the end for real construction tolerances.  Competing office cultures frequently war over this false dilemma - nominal or actual.  In Revit, dimensions serve to report for the size of the object to the to the foot, the inch, the 1/8th inch and even nearest 1/256th of an inch (a seldom, if ever, needed level of accuracy.  These “styles” of dimensions can be set to different parameters, but can report dimensions to unrealistic accuracy, just as reporting nominally, leads to problems.  Accuracy should not be confused with precision, which both early schematic and later detail design thinking alike can benefit from.

Living Dimensions on a Module

Brick and concrete masonry offer a system of measurement offers one example of  the use of simple, actual dimensions.  Material sizes are incremented to a module.  In the case of brick, a standard unit is 7 ⅝” long, 2 ⅔” high, and 3 ⅝” deep.  Add ⅜” mortar joints and stack three high, and the face module becomes 8” x 8”.  The corresponding concrete masonry module is 8” x 16”.  An elegant progression of dimensions becomes available as they are assembled: 8”, 1’-4”, 2’-0”, 4’-0”, 6’-8”, 8’-0” and so on.  These are not nominal dimensions, they are precise, with no leftover fractions to build up and keep track of.  Precision, to an 8” module is useful in both concept and detail, in resolving plan and elevation.  Many of the overlapping systems in a building design lend themselves to modules, Regular structural grid modules help set up useful basis for efficient subdivision.  Finish materials frequently come in set lengths that are useful to repeat.  Dimensional modules at various levels provide a framework at for consistent size, shape, rhythm and scale for the building as a whole.  A complex system becomes simple and understandable.

The flexibility of the tools in Revit for producing a design open up new ways for coordinating dimensions at all phases of the process.   In layout, a repeating module of spacing can be chosen to form a series of columns, openings, or room partitions as a rule, and exceptions in spacing made, but kept limited to, say, 1’ increments. (or at smallest, 1” increments). Dimension strings in Revit are “live.” (Here's a good post).  Move a wall, the dimension reading changes, touch a wall, and the dimensions “go live” and can be overwritten with the desired number to move the wall.  Precise placement of elements comes easily, and locations will lock into and flex along a module instantly.  In AutoCAD language, you would force movement increments by a “snap” setting, but these dimensions are on steroids. 

Dimensional Reality of the Model

Rules of thumb abounded in the days of hand drafting.  After the sketcher sketched,  the presenter presented... loosely, in terms of accuracy.  Then, work passed on to the drafter for tedious scaled delineation, with strings of dimensions added at the end of the process.  These were exhaustively solved mathematically, if not geometrically. Towards the end, the drafter often had  to depart from scale to some degree to avoid too many painful erasures, applying the dreaded NTS (not to scale) notation next to the offending dimension.  CAD revolutionized graphically scaled accuracy in architectural drafting. Moving, stretching, erasing, redrawing of geometry was seamless, if not endless.  But CAD brought with it the Boogeyman of  Myopic Accuracy now possible, way beyond any tolerance possible in the field. Endless strings of any complexity of dimension could be resolved in detail to any fraction of inch.  A quick and spontaneous initial schematic CAD drawing was frequently too sloppy, using rough placement to keep thoughts uncluttered, just as in the days of the handmade presentation. Detailed drafters simply threw that work out and started over for working drawings.  

A new era has dawned.  The process of parametric modeling brings us back to reality, to the.concept of resolving to simple, yet precise dimensions, from beginning to end.   Using this logic of modular “snap” points can speed earlier design thinking, and still  remain valid through later refinement.   The whole forest comes into view, reinforced, not obscured by the sheer number of trees that make it up.  “Live” parametric dimensions can give an ongoing reading to the design team giving shape to the building, working elements to a coherent, guiding dimensional pattern. As more detail oriented thinking evolves, more refined, fine grain dimensions help describe the work, building on the original framework.

The Revit Concept - Past and Future

LeCorbusier's Modulor

Revit is conceptual; it is a software tool for virtual modeling in the practice of architecture that, for me, is at once a new paradigm and a revival of an older way of thinking.  The new tool, variously called "Building Information Modeling," (BIM), or "Virtual Design and Construction" (VDC), has been a welcome change in the field.

The Beginning

When I studied architecture in the late 1970’s at Cornell, I learned from the work of the modern masters: LeCorbusier, Mies, Wright, Aalto, Kahn, and some newer folks: Meyer, Stirling, Rossi, and others. Thanks to professors Colin Rowe and Mathias Ungers, we were also pointed back to the great precedents before the modern era, and pointed forward to the larger world around us. Design started with criteria for the program and the context. A parti, the big idea, was diagrammed and tested. Architectural elements, including walls, floors, roofs, and openings, built on the parti. These were the elements of architecture , with the designer sketching, drafting, and rendering, and, at times, building a physical model to work out the idea.

The CAD Era

Shortly after I went into practice in the 1980's, the digital age brought a new, helpful, but demanding tool into architecture: Enter Computer Aided Design and Drafting (but with special emphasis on “drafting”). Not purpose built for Architects, CAD had its beginnings in Aerospace. Any discipline could use it for any kind of delineation (I remember my surprise when I saw "Ångström" as one of the choices for setting the units, not just feet or meters). A new vocabulary came to dominate our work: Point, Line, Layer, Xref. The tool brought incredible accuracy, but its narrow focus often distracted from forming ideas and buildings.

CAD came to dominate how we developed designs and produced construction documents, taking the place of the team of hand drafters of past eras. Most simply used it for more efficient 2D drafting. AutoCAD did offer awkward 3D tools within its software packages, but these would go largely untapped. Outside applications crept in, like Sketchup and 3DMax, out of sheer necessity to see the building more fully. Adding and scheduling elements of the building remained a "one item at a time" process, with some assistance from the copy command and spreadsheet software. The computer had automated and integrated the working process in many fields in the 1980's and '90's, but not in architecture.

Back to the Beginning

By 2000, advances in computing started to offer a practical road back to the original focus of architectural design, and leave traditional drafting behind. Architects could begin to work directly in an integrated environment of the virtual building model that completely linked information, and creating a wide variety of 2D and 3D views automatically. When I became aware of Revit as one of these new accessible BIM packages 10 years ago, I jumped in. Away with machine drafting to trace out buildings in in a complicated sequence of glowing vectors and color coded layers. I missed architecture.  

Since then, I have been immersed in the virtual building information model. I am back to the conceptual basic building blocks of wall, column, floor, and roof. I now mold and describe forms, space, and functions as I learned in school. Endless cross references from drawing to drawing update themselves as details shift and change. I am writing this blog, Revit Reflections, to explore ways Revit has energized my work as an Architect, and, in many ways, brought me back to my roots.

The BIM Placeholder - Hold that Thought!

Architecture is broad in conception, but also intensely detailed.  Two distinct forms of thinking are needed to get a design off the ground and a building into the ground.  To resolve a design, the architect must branch out and explore, but also refine and nail down. Architects have a long tradition of how this process works: loose sketching of options, expressing  and presenting proposals for debate, for decisions.  Finally, design complete, there is a hand-off, and the process of committing to hard lines and exact descriptions begin.  Narrowing down is relentless, so that the many interconnected details can be addressed. Proceed one step at a time, and, above all NO CHANGES to the design. This split promotes two cultures in any practice: the dreamers and the realists, each working in a separate room.

The computer helped relax the thinking process in many fields. A writer of old would write by hand or peck on a typewriter, then wrinkle the paper into a ball, and start again. Editors with edits and printers with proofs each came in strict succession. A somewhat different workflow than now when using MS Word. We have become accustomed to an interactive process.  

Enter the Building Information Model. Architects compose and link a network of objects to describe the design, giving the building coherent form, proportion,enclosure, structure, functions, and so on. The schematic design serves as the overarching outline of placeholders for a large amount of detailed information that will eventually be resolved.

Schematic Design

Peter Cholakis, in his Building Information Management blog describes it:  "Some information is more appropriately located in the ‘geometrical’ part of the BIM object while other information is more suited to the ‘properties’ part, such as the specification. The specification is part of the project BIM, and objects live in the specification. In traditional documentation we would ‘say it once, and in the right place’, however with BIM, we want to ‘author it once, and in the right place, to be able to report it many times’. ...Take the analogy of a BIM object representing a simple cavity wall. The object will tell us the width of the brickwork and height of the wall. However at a certain point in the project cycle it is the written word that is needed to take us to a deeper level of information. It is within a textual context that we describe the length, height and depth of the brick. It is words that are used to describe the mortar joint and wall ties."

Construction Documents

Elements of the design are necessarily generic and simplified to start, giving power to organize  the project.  Elements are stripped down to their basic form as placeholders for extensive, interconnected detail to come. This is important in many fields.  A satellite engineer from Johns Hopkins Applied Physics Lab I know uses placeholders,  “At the beginning of a project, the exact nature of the content may not matter, or even exist yet. Or maybe having actual content would be too distracting from the problem at hand.”

Graphic and web designers have been know to use lorem ipsum, and even placekittens to hold the place of eventual text and images to help bring focus to the task of structuring the page or site.

Lorem Ipsum placeholder text

In the old school, the “design” has to be finished before before “detailing” begins. (Draw it Once!) Now the evolving design has a living backbone to support  a combined team effort. Concept and detail stay linked.  No risk of ever having to collectively crumple up the paper and start all over again. The building information model outline can adjusts, continuing to hold a hierarchy of details as they develop.

That is my vision for BIM in the workplace.  What is your experience?  Does BIM actually foster flexibility in design, increased collaboration, more integrated detail, or is the verdict still out?  Looking forward to seeing a dialogue in "Comments".

Magic in the Sketched Line

In its latest retro feature, Revit Building Information Modeling software can now show a view of a design as if it was sketched by hand.  I had been long awaiting this.  At least twenty years ago, a software called Squiggle cleverly offered to translate the cold hard lines of a design in AutoCAD to sketch form, warming the audience to a more humane presentation of computer aided drafting. What is it about the appearance of less certain lines and more ambiguous images that invite us in,  where mathematically perfect lines and images often repel?

A sketch is by its very nature spontaneous and rapid.  The thought is being born, not dryly reported.  The irony of a computer simulated sketch is that its seeming relaxed random line style is strictly proscribed. In Revit’s version the parameters are “jitter”, how the sketcher waves the line from straight, and “extension”, how much the sketcher overshoots lines at intersections.  The exact geometry has to come first, not the other way round as in the old school.

Long before computers, the original intent of a hand sketch was to quickly, flexibly translate thoughts to paper, the detail not yet completely known. A sketch was an informal study that allowed rapid iteration of ideas that were not predetermined: a stream of consciousness.  The sketch invited participation. You could see what you wanted in its more ambiguous play of lines.  Da Vinci’s flying machine is credible without quibbling about details. LeCorbusier's classic building typology is appealing and believable, abstracted to basic concepts.

Revit’s choice of the word “Sketchy” is perhaps unfortunate, since sketchy thinking doesn't share the trust that the sketch itself does. A sketch can hide things: flaws that would doom the feasibility of a design, or perhaps bring unmerited appeal through “eyewash,” like pretty composition or shading; a cloud or tree in the right place.  The architect’s “napkin sketch” is famous: the miraculous birth of the design. More often, though, this clarity comes as the design evolves and is refined.  Often the great napkin sketch, the parti of the building, is hand traced  over the final design drawings, much as Revit abstracts the sketch from a set of hard lines.

I tried my hand at input of concept using Revit’s new “sketchy” interface myself, rapidly outlining a series of walls and roofs to form trial concepts for a new building.  It was freeing, but was I fooling myself?. Even as I was able to stay in scale and form spaces to the needed sizes, as is only possible with some level of automation, I did experience more flexibility, less focus on distracting detail.  Hand sketch advocates on the team brightened up and felt more relaxed in offering ideas. 
The design came together. Magic? 

Crunching Areas in a Model

Architects are frequently hounded by the task of area tracking as they practice in the real functional and economic world.  Early in design, the  person drawing the design establishes, quantifies, parses, analyses, sorts, and re-sorts areas describing each function needed in a building. How to areas fit to opportunities for form?  How can and should areas be grouped, consolidated, separated?  And, of course, the bottom line, what area fits the budget? Building Information modeling is the ultimate tool to make this tracking work.

In past, drawings in the schematic design phase were famous for fudging the area numbers.  How else could the Architect draw up a guiding strategy as fast as the thought process, and arrive at the basic outline of the building plan? Design ideas come quickly, accurate accounting less so. The more complete the numbers, the more likely, with so much time invested in computation, that the plan becomes established and inflexible.  Hand sketched schematics require setting a scale to plan, and punching length and width into calculator. CAD improved the situation somewhat, with the ability to surround areas with a polyline that listed area. Facilities management programs can attach these areas to reports, but require extra steps not integrated into the design process as a whole.

Number crunching in Revit is straightforward, as shown in the Revit Wiki and the Revit Zone websites, citing two sources.  A building information model, as it is created in Revit, is at once a geometric, graphic and numerical data base.  On the plan level, a room is reported graphically bounded by walls or area separation lines.  This room can also be reported by any other of its properties, including its area, assigned department, occupancy, function, or anything else.  These properties can be sorted and reported in tables (like an excel spreadsheet), or in color coded plans alike.

Net Areas

The multi-clinic medical center shown is one example of design area tracking in Revit. When rooms are sorted by contribution to net area, the Architect can verify alignment to the user's program needs as a whole.  Using a ratio with gross area, the architect can test the efficiency of the proposed plan layout.  We can flexibly nudge walls, add, subtract, consolidate, rearrange, and test the patterns:  numerical feedback is immediate.  The graphics give us a clear picture of what is being accomplished, and may point out new directions.

Departments

Using the clinic center as an example, other properties can be assigned and tracked.  The designer as well as the building end user will want to see where individual clinics and their supporting services are proposed. The visual report in plan is immediate and convincing.  Drilling down yet further, we can see how sub-functions relate: private or public, served or served or serving.  Exam rooms and individual offices are the basic building blocks of this particular building program.  Lobbies, corridors, labs, toilets, and other functions serve these in the larger hierarchy of spaces.  These properties appear in tabulated, sort-able lists, and also can be tested and visualized with color coding in plan.

Functions

Many see the power of modeling for three dimensions early in the design process.  The model in Revit certainly provides this, as do many other software modeling packages like Sketch-up and 3dMax. Less tapped is the modeling of area early in planning,  This requires a true integrated building information modeler like Revit.

Revit and GIS

When in the throes of designing and organizing a new building, I am often struck with the notion that I am creating a map. Turns out there is an active debate on the subject: Graeme Martin of Spacial Vision covers the tip of the iceberg in BIM, CAD and GIS – what’s in a name? and cross references Dr. Anne Kemp's white paper “BIM isn’t Geospatial” …. Or is it?"   Is a Building Information Model, as produced in Revit, a small scale version of a Geographic Information System?  Are we on the way to an integration of the two?

The architect's lowly map correlates useful, interchangeable and connected information spatially, to rooms, architectural compositions, building systems, and individual building components.  Online, I have touched on debates about the merits of "little bim" vs. "Big BIM", the later being the highly interconnected, complex information database of sufficient magnitude to understand and manage larger issues of infrastructure.  I feel humbled with the vast promise of so-called little bim alone.  Just as google maps, the most accessible Geographic Information System around, has allowed us to explore a neighborhood or region, to navigate and learn,  Revit enables the design professional to travel through the design while it is being created.  

What are the real world examples of aggregated and coordinated models like mine in use in Big BIM?  I see it in sci-fi movies but tend to be skeptical that it is coming that soon. But, then again, I may be surprised some day when I zoom in real close to a building in Google Earth, and end up inside.

To BIM or not to BIM

Reflecting on an oft debated subject, I point to a well argued blog post:

(bim)x: Should This Project Be a "BIM Project"?.  The list presented weighs out costs and benefits, but two keys may be missing: flexibility and motivation.  A typical architectural firm, uninitiated in Building Information software (BIM), may well tick down the list to a resounding "no,"  When working in Connecticut, I was often reminded of an unofficial motto: "the State of Steady Habits". We are effective with old habits, and so it is hard to evolve to new tools.  In terms of leveraging new technology, how did it come about that the time honored use of the hand ledger was finally overtaken with automated spreadsheet?  In Architecture, what is the tipping point of moving from careful use of smaller amounts of personally thought out information to mapping out large quantities of interconnected data, both visual and quantitative?

Revit, Rev it, Revise it.

Rev It

According to Wikipedia, that great trove of obscure, often unsubstantiated facts, Revit, the architectural building information modeler, means Revise It.  To tell you the truth I had guessed it meant "speed it up" (e.g. "Rev up your engine").  Revise it makes more sense.  When we revise we are making adjustments based on new criteria. Parametric modelers (see my blog post, The Parametric Approach) revise as we think, as we learn. Less reason to "lock the drawings" and be tempted to become less responsive to disruptive new information as it bears on project.

Perhaps acceptance of parametric modeling among architects depends on temperament. Drafting culture has always relied on a "guardian" to keep a complex, linear document workflow together, taking top down direction from the designer and fleshing out the design in a predictable, linear manner. The new digital opportunity to comprehensively, logically, reliably improve a design at any stage of the work has opened a door for creative, rational types to stay involved throughout the process. The architect can apply substantial changes directly at any point in the process, which can either be taken as a threat to or breakthrough for efficient production. A different workflow presents itself, offering new ways to look at how and when to control the process of design documentation.

Revise It

In a way, BIM has always been with us. The earlier version has been "Build In your Mind," then translate to 2D representation. Going from personal vision to ink on velum has always been an an important, but often tedious process. This pattern changed with the new "Building Information Modeling" type of BIM.  Revit may or may not be faster than CAD, but is certainly more responsive. Changes can be mapped automatically to any and all drawing views or descriptions that are needed to keep the work up to date and coordinated The new tool can enable less linear, more collaborative ways of thinking. Architects now have the opportunity to revise the way we accomplish our work.