Tired of Verifying Code Required Clearances in AutoCAD? Incorporate Them in to Your Dynamic Blocks

No matter what your discipline, one of the tasks of a designer is to make sure that code or ordinance requirements are met. A lot of codes and ordinances incorporate clearance, spacing or directional items that must be complied with.  Verifying compliance is a regular task that could mean embarrassment or possibly a red tag and significant costs if it is not caught in the plans review but does get caught in the field.

Two common code regulatory agencies that have requirements that are perfect for incorporating into blocks are the American Disabilities Act (ADA) and the National Electric Code (NEC).

I have dealt with both myself, and it always adds a little more time than I would like to spend to verify that the necessary clearances are met – especially when plan changes happen.   Now this does not mean I do not want to do this important task, I just want to get it done faster!

In my current field of work, the NEC is what I deal with regularly, and an important concern is that of clearances in front of and around electrical gear. This is a safety issue, and if not met can stop a job in its tracks and possibly cause expensive re-work.

A few years ago I decided to address this by incorporating these clearances in the company’s master blocks. As the blocks got more detailed, they became more useful for not only verifying code clearances but also being able to verify quick electric room layouts.

Visual Clarity

Below is a screen shot of an electrical room without clearances shown.  When looking at this electric room plan, the non-electrical person will often assume the room is too big and has a lot of wasted space, which is something we deal with some building owners and architects.


Figure 1

We don’t want to waste space if possible, but as part of our design, we have to consider, future expansion, ventilation around equipment, and most importantly manufacturer’s and code required clearances.

Below is the same room with clearances turned on.


Figure 2

The clearances shown in Figure 2 above are on a non-plot layer called “E-clearances” (not defpoints).

Note: If you have a bunch of (or any) non-plotting notes and line work on defpoints – please don’t. Defpoints has a purpose, and it’s not for storing your coordination notes and linework.  If you would like an explanation as to why using defpoints is bad, check out the post titled “Layers are a piece of Cake” – my first ever FunctionSense post.

I typically leave this non-plotting coordination layer on as an easy check when there are background changes – to make sure we stay in compliance.

More Useful Data

To make the blocks even more informative, add supplemental data that allows you, your coworkers and any team members that you share your drawings with to stay informed on your design intent. In Figure 2 above, you may notice text in the transformer and clearance lines. The text in the clearance lines lets us know which code situation we fall in based on the voltage and material in front of the gear.  The notes in the transformer tell us what size transformer our layout is based on and how much it weighs in case it needs to be hung from structure.  This may also be helpful for any other team members that we share the drawings with.

Most companies, mine included, use a specific manufacturer as the basis of design.  One of the things I have also started incorporating in manufacturer specific blocks is an additional ‘Visibility State’ that lists the manufacturer’s reference data or specific application notes.

Check out this quick video showing some of the features mentioned above.


There are some pretty cool things you can do to increase your productivity by incorporating code required clearances and other useful data into your dynamic blocks.  Other items we commonly incorporate:

  • Ordinance required light pole spacing (based on pole height – visibility state, plots on drawings)
  • Coverage patterns for Occupancy sensors (based on multiple manufacturers with different colors, non-plot layer)
  • Coverage of Fire alarm strobes based on Candela rating (visibility states, non-plot layer)

Are you incorporating code, ordinance or manufacturer’s data in your blocks for coordination purposes?  If you have a unique idea, I would love to hear about it.  Leave it in the comments or email me.


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