Circulation Space at Doorways – AS1428.1 Compliance

I’ve posted more than enough news related blogs recently, so here is a long overdue tips and tricks post! This will only be of use to those in the Australian market, as it is a family designed to be nested into your door families to check door approach clearance, demonstrating compliance with AS 1428.1.

There are a few tools about but none of them really achieved the functionality that I wanted, so here is my version. Start with a generic family template as this will give you the required control. Rather than building individual families as per the above diagrams, I have combined all of the approaches for one side of the door. Whilst this might end up looking more confusing at first glance it is easier for users to actually use. It can be controlled by a visibility parameter (yes/no), so it can just be switched on in the door family to check compliance before being switched off again.  You can see at a glance whether any partitions or furniture etc. are impeding into  the approach zones, determine if any of the zones are clear, or if you have to move the door, or rectify it in another manner.

Set out your Reference Planes as per the standards guidelines.

Assign the required parameters, all very straight forward, with the only slightly tricky part getting the formulas right. Formulas are not my strong point, so I’m sure that they could be simpler/cleaner, but the family works. They are required to ensure that the zones adjust depending on the achieved clearance between your open door leaf and the opposite door jamb. Remember that each side of the door has different requirements, this family is for the side that opens away from the user.

Create new subcategories for each of the four documented approaches and assign a different colour to each so the zones are easier for users to identify. Create and constrain lines to the work planes. Add arrows with the same colour coding so it is easier to identify each approach extent.

 Load the family into your door families and create a new parameter for visibility. You will also need a ‘clear opening’ centreline to constrain to, but keeping this work plane centred (not on the family but the actual clear opening!) can be a bit difficult without over-constraining the family. Reporting parameters will have issues refreshing and will not drive the clearance family, so I found the best method was to create a work plane (for the centre line) and dimension it to another part of the door family, for example the jamb. Then create a parameter that is driven by a formula to ensure that it is always reporting half of the clear opening.

How this formula is worded will depend entirely on how your door family is built – e.g. (Width – (Structural Tolerance * 2) – (Stop Width * 2) + (Leaf Thickness + Tolerance – Stop Width)) / 2 + (Structural Tolerance + Stop Width). It’s pretty obvious formulas aren’t my thing, but as long as it works…

You can also use a ‘clear opening’ parameter to drive conditional formatting in your door schedule, highlighting a cell in red if the minimum door clearance is below the requirements.

The result is a family that can be added to all of your doors and easily controlled by users for viewing in either plans or 3D views. It allows you to identify at a glance whether the door should comply with at least one of the approach clearance requirements or not.

***Disclaimer: This family is intended to be used as a guide and aid for compliance checking, not as a tool to demonstrate compliance. As noted, my formulas and the general accuracy of the family cannot be relied on, but again should be used as a guide for you to create your own version based on current regulations.***

Useful families make for a betterRevit!