The answer depends on whether you’re starting with the original plans in another format e.g. PDFs, images or paper plans.

If part of your process is to convert the designs to a CAD format then I would suggest Scan2CAD.

Full disclosure: I work at Scan2CAD so I’m biased 🙂

If you are designing the plans in CAD from scratch then there’s no need for conversion software.

So I would recommend AutoCAD.

You may be looking at other applications because AutoCAD doesn’t ship with firesafety templates but as the AutoCAD community is thriving, there are a lot of resources out there.

Here’s some examples:

• Free library of fire safety symbols http://www.firesafe.org.uk/graphical-symbols-and-abbreviations-for-fire-protection-drawings/

• Building underlay plan: http://forums.autodesk.com/t5/autocad-lt-forum/fire-and-safety-templates/td-p/4395817

• Fire safety symbols (registration required.) http://www.cadforum.cz/catalog_en/block.asp?blk=12031

Please bear in mind that I don’t work in fire safety so take the advice with a pinch of salt. It would be great if there’s someone with who has experience in this industry could add their answer here.

If you’re looking for software that can also simulate fire sprinkler behavior, load, and range, you can opt for 3D design software or BIM software.  I personally use Revit, it’s intuitive and robust as a program. Plus if you’re already familiar with Autodesk applications, it should be an easy time learning the software.

Additionally, here’s an article that discusses some ways you can decide which BIM software is best for you – BIM Software Comparison