Revit Tips: Referencing Sheet or Back Referencing

Revit has a parameter built into views called Referencing Sheet (which is also known as Back Referencing). Referencing Sheet lists the sheet number that a view placed on a sheet is referenced from. For instance, if a floor plan on sheet A2.01 - FIRST FLOOR PLAN shows a section cutting through a wall and the reference on that sheet is 1/A3.05. If you look at view 1 on sheet A3.05, you'll find the section cutting through the wall. On that view title may also be a Referencing Sheet field telling you when you look at that view that the section was cut on sheet A2.01.

 

Pretty useful and logical right?

 

Unfortunately, the Referencing Sheet value doesn't always reference back to the sheet that you would expect it to.

 

Let's say you have a set of drawings set up as:

 

A0.XX General

A1.XX Site

A2.XX Plans

A3.XX Sections

A4.XX Elevations

A5.XX Enlarged Plans

A6.XX RCP

 

And you have a section that you want to place on a sheet in the 3.XX series. Why do you get a back reference number from a Site Plan (1.XX) or other view if you created the section in a Floor Plan (2.XX)?

 

Referencing Sheet lists the first sheet, in order, that has a reference to that view. So if the section mark is showing in the Site Plan, it will show as the Referencing Sheet on the sheet for that view. To change that, hide the section annotation in the Site Plan. The Referencing Sheet will then look for the next sheet to have the section mark.

 

Fortunately, if the Referencing Sheet is listing a view that is different from what you want it to show, you know right where to look because the Referencing Sheet parameter tells you what sheet to look at..

 

One place where Referencing Sheet values can get more fouled up is with Dependent Views.

 

Let's say you've got a floor plan split into two areas, A to the west/left and B to the east/right and both plans are Dependent views off of the same Parent view. If you have a section, elevation or other callout in Area B, then when you place that view on a sheet, it may very well list the sheet that Area A is on as the Referencing Sheet. This is a bug related to how Dependent views relate to each other via the Parent view. What you will need to do is go into the view for Area A, uncrop the view, find the section/elevation/callout annotation for that view and hide it manually.

 

It can be a frustrating process at times and obviously the tool needs some tweaking, but all in all it's a useful tool and beats entering the information manually.

Revit Tips: View Title Wrapping

View title lengths can sometimes wrap in awkward ways in Revit.

For instance, a view may be named "ENLARGED POWER AND COMMUNICATION PLAN - EIGHTH FLOOR - JS-1 ADA" but when it's placed on a sheet, it ends up looking like this:

ENLARGED POWER AND COMMUNICATION PLAN - EIGHTH FLOOR - JS-1
ADA

​
Not exactly what we want to see graphically.
If you go into the View Properties, you can see two parameters under Identity Data that can help you fix this. The first is View Name, which is the name of the view as you will see it in the Project Browser and as it will appear on the sheet.
Below View Name is Title on Sheet, which will override the View Name on the sheet. You can also control where the line break will occur in this parameter by holding 'Ctrl' and pressing 'Enter'. Using this approach, we can change how the View title appears on the sheet to something a little more graphically sensible:

ENLARGED POWER AND COMMUNICATION PLAN
EIGHTH FLOOR - JS-1 ADA

Additionally, since Title on Sheet does not need to be unique, you can use this parameter to give multiple views the same name on the sheet.

Title on Sheet is something that should generally be used sparingly, only when absolutely necessary. Having to manage the Title on Sheet parameter as well as the View Name for every single view could lead to confusion and consume time better used on other aspects of the model.

BIM Dictionary: BIM

So what exactly is BIM?

Well, for starters, BIM stands for Building Information Modeling, which tells you a little, but not nearly enough. The simplest explanation I have heard, and probably my favorite, is BIM means we build the building in the computer before it's built in the real world.

The Building Smart Alliance, which produces the National BIM Standards, has described BIM as:

Building Information Modeling (BIM) is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle; defined as existing from earliest conception to demolition.

What does that mean though?

For one thing, it means that instead of drafting two dimensional lines to represent, for instance, a wall, a BIM user instead picks a wall tool, then selects a wall type, picks a start and end point and voila, you have a wall. In plan, this wall may look like anything you may have drafted in CAD. However, this wall also exists in 3D. It has finish information associated with it. It has layers of construction, i.e. gypsum wall boards, tile, 3 5/8" metal studs, plywood, etc. The wall has a sound rating, fire rating, wall type for tagging, specification section references and much more. This is where the "I" in BIM comes from.

This information allows for much more advanced levels of coordination. For instance, an appropriately built BIM model can calculate the amount of gypsum wall board needed in a project. Or tile, plywood, metal studs, concrete, paint, etc. Any material used in the project can be estimated from the BIM model. Some structural firms even model the rebar used in concrete pours.

Additionally, by modeling systems in three dimensions, BIM software allows designers to do detailed Spatial Coordination, checking the locations of the designed systems of the various disciplines against each other in 3D, including clearances. This illustrates to designers instances where a fire protection pipe might run into a mechanical duct, or where a mechanical duct may run along the access clearance of a run of cable tray. By modeling the systems in 3D, this coordination becomes easier to see, hopefully reducing costly changes in the field during construction.

There are many more facets to BIM, too many to cover succinctly in a single post. Put it all together though and what BIM does is allow designers to manage and coordinate the design of increasingly complex buildings in a more manageable way.

A note on software

There are an array of choices when it comes to BIM software. BIM is as much a process as it is anything else, no one piece of software embodies BIM.

Revit, ArchiCAD, Bentley, Allplan and others all have their strengths and weaknesses as BIM implementation tools. As you can tell from the title of this blog I will be focusing primarily on Revit and software and processes that interface with Revit.

The reasons for the focus on Revit are simple. While Revit is obviously not the only product out there and is not as market dominating of BIM as AutoCAD is of CAD, it is the dominant software in the market, which is why our firm uses Revit as opposed to some of the other products.

So the BIM conversation will commonly be couched in general terms, but when I discuss specific details of software, it will be in terms of Autodesk Revit's latest release.

A BIM Perspective

There is no shortage of blogs about BIM and Revit, so why add one more voice to the chorus?
To understand that, a little explanation of who I am is necessary. I work for a small architecture firm in the Dencer area as the company wide BIM coordinator. I have been with the firm for just shy of three years and have seen us grow from a staff of four when I started to a staff of approximately twenty today.
So in this case, it's my hope to use this venue as a resource for my own co-workers and other interested readers with some general BIM knowledge and tricks as well as to provide some perspective to the AEC public on BIM in the small business.
In many ways small AEC firms approach BIM no differently than how many other firms handle BIM. In other ways though, we must approach things differently than a medium or large sized firm does.
Our company president also made the fairly unusual decision to go all-in with BIM, executing all of our projects using BIM software rather than CAD.
Some of the material presented here will be shortcuts, tips and tricks that I or others have found in executing BIM projects. Some posts will highlight difficulties and challenges. Others will outline presentations I have given to staff as a reference. Other posts will be targeted at non-users, such as marketing staff and some project managers who may never open BIM software themselves but who still seek to understand the lingo.
A final purpose behind this blog is more personal. It's to keep me thinking critically and creatively about the work I do and the field I am in. If no one else gets anything else out of this beyond that, then I will consider this endeavor a success. That said, I hope you, dear reader, will find value here as well.

In the beginning...

... there was the stylus.

And it was good.

The stylus evolved by small steps into the pencil, and, later, the pen. With these tools architects and engineers plied their trades for generation upon generation, drafting on paper, parchment, vellum and mylar. But there were limits. Hand drafting took a great deal of time, high quality reproductions were difficult to produce and stacks of paper and trace piled higher and higher.

Then came CADD.

Computer Aided Drafting and Design brought the AEC field into the computer age, promising faster, more reproducible work which could be produced in less time. CADD slowly grew to include three dimensional computer models and renderings. But there were limits. For all it's sophistication, it could easily be fudged, it wasn't very smart and proper three dimensional modeling for spatial coordination was time consuming and not very effective.

Now there is BIM.

Building Information Modeling has taken CADD to the next level. Instead of drawing lines that represent walls, you select a wall tool and in one quick stroke model the wall in three dimensions, with built in information such as layers of gypsum wallboard, brick, air spaces, structural support type, fire ratings, acoustical qualities, wall types and many more. Coordination within a project discipline has been brought to a new level, which coordination between disciplines going even farther when models are linked. Many modeling programs, such as Revit, can even be linked with software designed for specification writing. BIM has its limits, but right now, it is the leading edge in the AEC world.