Architects in
Singapore are required by law to design in compliance with Code on
Accessibility in the Built Environment 2007 (Barrier-Free Accessibility Code).
By creating special Revit families, we can check some of these requirements that
all architects are familiar with. In this example, we can modify a Revit door
family to enable Minimum Doorway Manoeuvring Space checking between the door
and other model elements such as walls. The evaluation can be determined by
hovering over a door to see clearances or by using Revit’s Interference Check
tool. This door type specifically tests minimum front approach clearances for a
door as defined by Accessibility Code 2007 clause 3.8.4, as shown in Figure 1. These represent very common
door clearance conditions.
Figure 1 – Minimum Doorway Manoeuvring Space (Accessibility Code
2007)
Our custom door
will allow Minimum Doorway Manoeuvring Space checking to be used in two ways:
(1) By hovering over a door, or (2) By using the Interference Check tool.
(1) By hovering over a door, or (2) By using the Interference Check tool.
When we hover over
the door type, outline linework displays to indicate the Minimum Door
Manoeuvring Space clearance area. Similar display occurs when the door is
selected.
Our custom door
contains extrusions that represent the 3D volume of the Minimum Door
Manoeuvring Space clearance. Type Parameters and Formulas are used to control
the extrusion location between different door sizes and wall types. These
extrusions are hidden in the project views but allowed the user to turn on or
off in views via a visibility parameter. The families also have the 2D graphics
as an object style to allow the user to turn on or off on floor plan views.
Figure 2 – Hovering over door displays Minimum Door Manoeuvring
Space clearance boundaries
Figure 3 – Extrusions in door family
Even though the
extrusions are hidden in the model, Interference Check detects collisions
between them and other objects.
Figure 4 – Highlighted wall interferes with Minimum Door
Manoeuvring Space clearance
Figure 5 – Visibility of 3D extrusion and 2D boundary lines can be
control by Type parameter
Checking Minimum
Door Manoeuvring Space clearance is an architectural task that happens on most
building types other than single family residential. Using customized door
families will make this process easier and ultimately reduces errors in our
design.
(Reference: Autodesk WikiHelp. ADA Door
Clearance Checking using Revit Interference Tool)