Saturday, July 26, 2014

PDFs and BIM: A trilogy of posts investigating what the PDF format’s role may be in strategies transitioning the industry to BIM? First part: PDFs within current AEC – Important yet neglected?

PDF as a digital file-format is generally frowned upon by those in charge of creation and management of project information within the AEC industry.
It is being treated as something one puts up with until something better comes along. 
This approach is somewhat surprising considering that in most contemporary construction contracts PDF’s as the digital representations of drawings have often higher standing than model files or even DWGs.

In the still widely practised 2D information flow, where simultaneously PDF/DWG files get exchanged by project participants, the PDF’s do get used by those not CAD literate, but all further work on coordinating or assessing the data (for example creating a BOQ) is usually done on the DWG files. The technical people that are in need of using PDF’s within their CAD environments tend to turn them into DXFs (often ending up with zillions of fuzzy sub-elements), JPEGS or to lay them under their digital drawings.
In principle there is nothing wrong with these practices, what is questionable, why there are no better technical readers/managers for PDFs to make them more accessible by those less interested in going full CAD?

The non-direct originators of the information (say, main- and subcontractors) together globally handle billions of PDF’s daily, for the purpose of validating, coordinating, measuring, specialist-detailing, logistics planning etc.
One would presume a chunky market to be there for developers of PDF focused tools.

Sure, there are programs on offer with ‘advanced’ viewing facilities for PDF files, measuring, notating even a bit of layering and cross-comparing but few tends to go much beyond what Adobe’s Reader provides. Could the problem be in lack of interest from Adobe to step up its offering for the AEC or are there some other reasons behind the scenes?

Some sophisticated Cloud Document Management systems claim to have solved the issue by focusing on the even bigger issue with PDFs that is managing the quantities they tend to be coming in. Their philosophy builds on the idea that, forget viewing and analysing if you cannot locate the correct file from thousands and thousands of others in the project directories. This is a very valid point as the quantities drawings and consequently PDFs are produced at are totally out of synch with what is reasonable or manageable. Unfortunately these DocManSystems do not go far enough into the content of the PDF’s, sticking mostly to treating them as only digital representations of the PAPER drawing.

Yes, one can search and sort large numbers of files by name, author, revision, discipline or whatever on their platforms but these type of metadata and the searching engines are of limited use for, say façade-subcontractors that need to quickly locate ALL relevant (but ONLY) relevant sheets from the electronic piles-of-files.
Those arguing that the common document structures DO give specialist users easy gates to locate data applicable to them may do some research on claims raised by/against parties missing out on vital project information through hasty filtering of data or indeed rebutted claims because contracts force all participants to have ‘all of the documentation read in entirety’.

In the past, I have written about ArchiCAD’s (Graphisoft) excellent ability to handle PDF’s, both in quantity and quality – the second applying to the quality of work offered to the users.
Two points to illustrate this claim (based on Version 16 – 2 years outdated ArchiCAD and used on a clunky computer):
Numbers: One can import literally hundreds of PDFs into one file with little impact on performance. These can be placed in plans/elevations/sections making them an excellent base for either 2D or 3D based work.
Spatial: by being able to place PDFs in vertical views as well as plans, instant references are at hand to check validity of drawings and cross reference between views.
Then, there is the ‘trace and reference’ command to assist with colours, opacity and the magic slider for interrogation purposes!

Even though I’m happy to be singing praises to ArchiCAD on this particular topic, the point I wish to make is not how this is the only or even best software to use to spatially assess large numbers of PDFs.
There may be many others; there could easily be much better ones out in the field handling PDFs. Also, it is only a part solution to the problem as there still is a large component of manual labour needed to sort and select the files one want to import into a ArchiCAD.

There are some important questions emerging:
Why is there no more discussion on this topic amongst experts?
Why are there no more efforts made to guide PDF users through thousands of drawings by the originators? (drawing list that themselves go over many pages are little use);
Why can’t we get the numbers of drawings significantly reduced and cut out a lot of useless padding?

Is the answer on these questions in the simple and sad fact that PDF’s are viewed as ’backwards parts’ of the digital AEC revolution that will disappear soon enough as we all rush towards the promised BIM Nirvana?
Or is it because few take the time to really understand what happens to the construction data in the real world, away from fancy BIM Taskforce Groups and BIM Implementation Strategies and fully appreciate the strategic place this format holds within both current and likely future workflows?


  1. In my experience, the cluster of companies that collaborate in making a building, have no straightforward, standardised way of working together. Some folk cannot cope with *.docx files or the "new spreadsheets". One company will xref in a *pdf instead of asking for an autoCAD *.dwg file, while another needs cad files to be backsaved. Some can't cope with sharesites, lineweights instead of colour tables, paperspace tabs, or even relative xref overlays. The one thing that is held as a standard is the *.pdf file - whether a drawing, a schedule or a full specification, the *.pdf never gives anyone in any company or department problems. They can even cope with 3D *.pdf files and cad produced *.pdf drawings with layers. *.pdf file scan be opened on tablets and phones, popped on pen drives, DVDs, e-mailed or loaded into the cloud. When sending a spreadsheet, document or drawing - whatever the native format may be, it is always a good idea to also (or instead) send the *.pdf of it. It's like a fixed in stone snapshot of what the author intended the original to look like. Adobe has moved on -- you are able to insert pages, convert in and out of formats, snap to lines in a cad generated *.pdf, select and search text. The 3D stuff generated by Bentley is absolutely essential for 3D clash resolution.

  2. ArchiCAD 18 allows you also to explode vectorial PDFs, practically converting them to 2D CAD files. This is a very, very usable magic!

    As for the rest ... people in the industry are in really very computer illiterate, and know only what they perceive is required. Downloading a large file from a cloud service is a problem. Can you burn me a CD? Yes, I can, but I will not!

    PDF is the only file format where you can be sure that the recipient sees EXACTLY the same thing on his screen that you do. Everything else - even IFC models - depends too much on the viewer software and the ability of the (remember, illiteracy?) recipient to open, view and interpret the contents.

    As for the models, IFC is the best there is, as 3D PDF tends to be large and clunky, and intimidating to the average construction industry practitioner.

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