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.

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.