Sunday, March 30, 2014


A couple of weeks ago I finally received my complementary copy of "Renaissance Revit" a wonderful book by Paul Aubin that came out late last year.  It came because Paul was kind enough to ask me to write the Foreword, and it was so long in coming because of the vagaries of the UAE postal system.

Over a year ago I had a bit of a go at modelling a corinthian capital in Revit.  It was an interesting exercise, and I was quite proud of my efforts at the time, but I have to say that Paul has been much more persistent and systematic in pursuing this goal.  In the process he has produced a major contribution to the "Broadening of BIM".

There is a rather sad tendency to see BIM in narrow business terms.  We allow our lives to be defined by time and money, percentage and profit.  BIM is just another nail in the coffin as we sit at our workstations like battery hens laying eggs on demand.  (Which is pretty much how I saw a career in architecture in my early twenties when I abandoned it to become a bricklayer, which seemed like a suitably subversive thing to do at the time)

I am carrying a torch for a broader definition of BIM: BIM as the new pencil, an all-purpose tool that can be applied in a wide variety of contexts, a vehicle for visual thinking.  Clearly Paul is also a firm believer in this wider vision.  This book is a wonderful way to achieve 3 goals simultaneously.

Master the intricacies of the Revit Family Editor
Gain a deeper insight into Classical Architecural Form
Broaden you vision of the uses of BIM

One thing I really like is Paul's open-ended approach.  Time and again he offers alternative methods and encourages the reader to make their own choices.  This is the opposite of rote learning (sadly too common in the "Teach Yourself Software X" genre)  But if you prefer, you can follow step-by-step instructions.  Paul has a very clear and relaxed style for guiding you through.

Not many will take the extreme approach that I did, but it's a tribute to his skill that it worked for me.  I took the liberty of skimming through large sections of the book and then striking off on my own from memory.  From time to time I had to dig back into the text for clarification, and the family I made was very different from any he presents, but it is also quite clearly inspired and informed by his work.  He took me to a new high over the course of a single weekend, with the promise of much more to come.

I spent a couple of hours drafting in 2d.  This is not part of the book, perhaps it could have been, but it was a response to Paul's deep insight into the proportions of classical mouldings, which really got me going.  Revit is a wonderful 2d drafting tool: much neglected in this area.  I sketched up 2 or 3 versions of the Tuscan order, based on photographs I have taken over the years.  Now there is no universal agreement on classical form and nomenclature, never has been.  In the end it all comes down to personal judgement of what is appropriate in a given context.  Paul manages to convey this difficult reality without sowing confusion.

Having clarified my ideas about what is fixed and what variable in a Tuscan column, I set about to make one.  Quite early on I decided to make a highly simplified version, suitable for schematic urban design studies.  This is the topic for one of my presentations at RTC Chicago in June, so it seemed useful to kill 2 birds with one stone.

I ended up with something intermediate between the coarse and fine versions that Paul incorporates within his Tuscan family.  I'll have a go at that another time.

One of the new tricks I learnt from this book is "Maximum Segment Angle"  I won't describe this in detail, (you need to buy the book), but it's a nice little trick. It gave me a method for switching between round & square versions.  I used a different trick to switch between column & pilaster (the sliding void)

Just like Paul's families, this one is a real column that responds to the floor-to-floor height by scaling itself up and down proportionally.  I started to place columns and pilasters on an imaginary building to demonstrate its versatility.

Then I decided to use a historical reference.  Why not Palladio.  Rather perversely, I then chose to embed the column inside another family, which somewhat negates the level-to-level approach of a Revit column.  Still useable though.  I'm developing the "buildings as families" idea for my Urban Design studies.  I started with Villa Piovene, slightly obscure, but an interesting location on a ridge overlooking a small town.  Turns out that Bing Maps shows this part of Italy at a much better resolution than Google Earth (by the way)

 Zoom in on the section at top right of the image above.  I was rather proud of that.  Justifies a BIM approach to history of architecture.

Next I decided to tackle Villa Saraceno, which sits on it's own in flat open farming country.  One of the fascinating aspects of Palladio's villas is the way they sit on their sites, how they relate to barns and other ancillary structures.  Different approaches in different contexts, but all recognisably cut from the same cloth.

That was one weekend frittered away.  Next weekend I found myself doing Michaelangelo.  Still taking an urban design approach, and starting with the Campidoglio, then putting it into context.  Before long I found myself mapping out the whole of central, historic Rome.  In a broad-brush kind of way.

I'm training myself to work fast, broad-brush, capture the essential structure of an urban composition as economically as possible.  Just a little insight into my preps for RTC Chicago in June.

But let's get back to Paul's book.   There it is sitting on my coffee table, filling my head full of tempting possibilities.  I'm going to get a lot of mileage out of this.  Here's another glimpse between the sheets.  (as it were)  Nice bit of fluting there.

If you would like to delve a bit deeper into the family editor, and / or   if you are a closet classicist ... get yourself a copy.  It's worth every penny.

Wednesday, March 26, 2014


Continuing where I left off on the Gherkin a few weeks back.  I have summary sheets to take you through the 3rd pass.  We will cut out the wedge-shaped voids from the floor plates, which spiral up the building six floors at a time.  6 floors, each with 6 lettable office areas.  The voids link these spaces together, bring light deeper into the building, facilitate air circulation, create interesting breakout spaces, allow for stairs linking one floor to the next.  It's a very interesting device as we shall see later on.

Next we will create black bands that spiral around the outer skin.  They trace the path of the voids behind.  We will also delete some panels at the bottom to open up an arcade at ground level and to define the entrance to the building.  And while we are at it we'll create a simple extrusion to represent the core rising through the centre of the building and housing the lifts, stairs, toilets, service risers.

To complete the third pass we add cladding to the frame.  In cross-section this is diamond-shaped, picking up on the theme established by the outer glazed skin.  We will set it up so that it can be hidden for selected instances, revealing the frame beneath. 

The summary sheets take you through the process of building the third-pass version of the Gherkin model.  I avoid lengthy detours to explain why I have chosen this or that method.  So just for fun I am going to add in a section here that mimics an FAQ format: questions and answers that expand on some of my methods.

Why do I set the hosted points almost at the end, but not quite. 

It's just a bit easier to know what you are selecting if points are not exactly on top of each other, just in case I need to say rotate the point later.  In this case it's also an opportunity to show students another feature of the Revit massing environment that they can use in future.  These exercises are intended to take "interest in BIM" and "interest in Architecture" and let them feed off each other, heightening the learning experience.

What is the brilliant DTP programme you are using to lay out your pages

Silly question.  I love to use Revit to combine images and text.  The images are screen shots captured by the windows Snipping Tool.  To capture the snipping tool itself, I can always use One Note, also one of my favourite tools.  Of course it would be most wonderful if The Factory would put greater emphasis on improving Revit's Desktop Publishing capabilities with each release.  Wouldn't we all love a better text editor ?  How about some basic image formatting (crop, brightness & contrast, drop shadow)  Images as links would be nice. 

My point is that for many companies, Revit is pigeonholed as a documentation aid.  The whole "seamless integration from concept design to facilities manangement" thing is stumbling at the first hurdle.  I would love to use Revit for concept design reports, not just by exporting "some of the images" but by compiling the whole booklet directly from my Revit model.  It can be done ... but it could be better.

What do you do when the information to hand is inadequate or ambiguous ?

What can you do ?  I make my best guess.  In some ways this is the best part.  Trying to figure something out, follow the clues, join the dots.  Don't be scared.  By building an inaccurate model we can stumble on the right questions to ask, the right information to search out.  For example.  The main entrance.  It's clear that there are a series of wedge shaped cuts in the floor slabs and glazed screens set back from the edge, but exactly what the angles are and how far back the screens are offset ... I'm not sure. 

The point is, we are not aiming for forensic accuracy, our goal is to gain deeper insight into principles, to learn lessons that may be useful in other contexts.

Download the files from the links below.



as before the summary sheets are pdf files designed to help you build the Gherkin model. 

The gherkin studies file is the Revit model itself, at a slightly more advanced stage than described here.  Summary sheets for the next stage will follow as and when I find the time.

Sunday, March 23, 2014


I have a weekly training session at GAJ called "Intermediate Family Editor".  It is aimed at people who have been using Revit actively on projects for a year or two but haven't got too far with the family editor.  This post is a revision aid for that class.  It's fairly basic stuff, but some of you may find it useful.

We are going to make some wall-based families.  New family: Metric Generic Model wall based.  This opens in plan view.

Note the 3 ref planes: "Centre Left-Right",  "Wall" (on the centre line of the wall) & "Back" which is locked to the face of the wall with a zero dimension.  I'm not really sure why it is called "Back" since it is locked to the "Placement Side" of the wall, which many would consider to be the "front".  Perhaps the idea is that this refers to the back of the object which we are going to place on the wall.  But what if that object is going to be a void which cuts into the wall?  Let's move on.

Note also the text object used to label the Placement Side.  This is just a dumb text object.  You can edit this or move it to the other side of the wall and it won't have any effect on the elevation view called "Placement Side"

So let's go to that view and draw some more reference planes.  Two of them are parallel to the centre F/B and equalised with a constrained dimension.  The third is parallel to the ground.  Add dimensions and label them as Width & Height.  Make these instance parameters.

We're going to make some geometry now, and we want to lock it to the ref plans and the level.  We don't want to lock it to the wall by mistake.  We could hide the wall using the sunglasses.  Instead we will simply pull the base of the wall down a little way so that we can see the Reference Level clearly.  Next set the work plane to "Back".  On the "Create" tab, select "Extrusion".

Choose the rectangle tool.  Pick 2 corners.  Lock the 4 padlocks that appear.  Finish extrusion.  Note that the extrusion projects backwards through the wall.  I don't understand why this is.  Could it be a mistake in the way the template was originally set up ?  Not to worry.  Go to plan view and draw a reference plane.

Place a dimension between this new plane and "Back".  Make sure you are picking the ref plane, not the face of the wall.  Label the dimension with a new type parameter called "Depth".  Select the extrusion, and use the shape handles to drag it inside out.  Snap on to the new ref plane and lock the padlock.

That's basically it for our first family, but we need to test it.  Select the wall and rename the type as "150"  That's the thickness of the wall as it comes out of the box (Metric Template)  Duplicate to make a new type.  Call this "250" and edit the wall structure to make its thickness 250mm.  Now that we have two wall types,  we can swap between them to check that the family will behave properly on walls of different thickness.

Before using a family in a project, it is good practice to "flex" it.  Basically you need to vary each parameter, one be one to check that it is behaving as expected.

Start a new project.  Create a wall.  Go back to family editor, "Load into Project"  Place several instances.  Set up two types with different depths.  Experiment with the instance values for width & height.

In the project browser, find the family, and rename it.  At GAJ we use 2 digit codes in our naming conventions.  38 refers to "wall features" ... could be panels like this one, recesses, niches, decorative plaques ...

Now we can go back to family editor & make a new version. When we load it back into the project it will be recognised as a different family because we gave the original version a new name.  Add 4 new reference planes.  Create dimensions and label them as "Border Width" (Type Parameter)

Edit extrusion.  Draw rectangle. Pick the 2 outer corners.  Lock the 4 padlocks.

Load this new version into the project and place a few instances.  Once again, create 2 types and experiment with the instance parameters for width & height.  Choose one instance of each type, and set the elevation to zero.

Notice that despite the different border width of the 2 types, Revit interprets the lowest point of the extrusion as the origin of the family in both cases.  This may be what you want.  Alternatively, you may want to have a consistent origin point, let's say the reference level.  Here's how.

Back in family editor, draw a ref plane that coincides with the ref level and lock the padlock.  Select this plane and check the "Defines Origin" box.  Load into project.

Note the now origin location.  By the way, we didn't need to do this with the first version of the family because there was no geometry projecting below the Reference Level. So let's move on to the third version of the family. Don't forget to rename version 2 first.

New family.  "Metric Profile".  Add four ref planes below the default horizontal plane.  Constrain them with an equalized dimension string.  Add and overall dimension and label it "W".  Create a vertical ref plane to the right of the existing plane.  Add a dimension and label it "T"

Now use a formula to make "T" change in proportion to "W"  (T = W/10)

On the "Create" tab, choose "Line".  Uncheck "Chain" and start to draw lines.  We unlocked the chain function so that we can lock each line as we draw it.  Draw 4 lines, locking them as you go.  Close the loop with a semi-circle.  Choose the "Start-End-Radius Arc".  Pick the two end points and feel it snap to a semi-circle.  Flex the family to check that it resizes proportionally as you vary "W"  Load the profile

Delete surplus reference planes (the 4 outer planes) and parameters (Depth) On the "Create" tab, choose "Sweep".  "Sketch Path".  Pick opposite corners.  Lock the 4 padlocks, finish path.

select profile.  Choose the family you have just loaded.  Note the rotation.  We want it to lie flat against the wall face.  In this case it can be achieved by selecting a rotation angle of -90.  Finish the sweep.

The last step involves linking parameters.  We will use the small "associate family Parameter" button that resides at the end of the line for each parameter.  Find the profile in the project browser.  Edit properties.  Click on the button for the "W" parameter.  Associate it with "Border Width".  The "Border Width" parameter will now act as expected, but instead of controlling an extrusion directly, we are controlling a sweep via the nested profile family.

Load into project.  Place a few instances.  Create types and flex the instance parameters.  You can go also back to each family and add a material parameter.

So we have created 3 wall-based panel families.  These are projecting panels, but we could just as well have created voids that cut into the wall surface.  You can probably think of all kinds of variations on this type of family.  They could represent plaster mouldings, grc components, notice boards, wall-fixed mirrors with moulded frames.   I hope some of you will find this useful.