rainbowdeams discussion page

While Municipal authorities that process Building Permits are not obliged to accept digital documents in place of paper, the benefits of a digital process include:

• Time saving on some functions such as applying stamps and measuring the areas of complex shapes
• Plans can be archived together with letter and tabloid size documents.
• Space saving compared to storing paper plan rolls
• Ease and speed of document retrieval and electronic transmission
• Environmental benefits of reducing paper production and deforestation

FILE FORMATS
Acrobat .PDF and PostScript file formats contain paper size information that enables them to be printed to an intended paper size (at 100% scale unless the print is manually scaled down to fit a smaller sheet of paper).

Both .PDF and PostScript images can be combined into multi-page files that make working digitally with a multipage set of drawings quicker and easier for Plan Checkers.

DRAWING SCALE
CAD drawings, once created into a PostScript or PDF format file, can be printed to the specific scale and size of page / paper intended by the original author of the design and drawing. Digital files that will have plan checkers notes added to them should be marked up with notes and stamps using the same printed scale and page size as intended by the original drawing author.

MARKING UP DRAWINGS WITH PLAN CHECKERS NOTES
Once received by a plan checker, PostScript or .PDF image files can be opened in an Image manipulation program such as Adobe InDesign or GIMP. Adobe InDesign needs to be purchased, but Software such as GIMP is open source, meaning that it is freely available, can be freely distributed and used commercially, and is ideal for “testing the system” before making the switch to digital. Both Adobe InDesign and GIMP have their own native file formats that allows one to work on images in “layers”. The original PostScript or .PDF drawings become ”base” layers over which a new layer of notes and stamps can be created by the Plan Checker. Once the work is complete the base layer and notes layer can be “flattened” into a single PostScript, .PDF and other common image format file.

In GIMP, distances can be measured off the image in most units, but at this time the out of the box installation of GIMP can only measure areas in pixels. To assist with measurements, the image in GIMP can be rescaled to “full size”. In order not to lose image quality or creating unwieldy file sizes, the relationship of pixels per inch to image size needs to remain constant. So for example, an 11″ wide drawing at 100 pixels per inch (PPI) and drawn at a scale of 1:100, can be rescaled in InDesign or Gimp to be 1,100″ wide at 1 PPI (ie “world” size), without changing image quality or file size. One would just have to remember to scale back to the correct paper size before saving so that the image can be printed to the correct scale on the correct size sheet of paper.

Adobe Acrobat Reader is able to verify digital signatures by Registered Professional designers, and Local Authorities should clearly define the standards they require for submission of digital drawing packages, to ensure efficiency and productivity.

Comments or questions, or if you would like a demo, please let me know.

Richard Dohmeier
Rainbowdreams Design
www.rainbowdreams.ca