Feature
BIM STAGES
The advantages of BIM during the planning and design phases
of a project have been instrumental in both documentation
and information sharing, as well as automating the tedious
processes of measured bills of quantities, updating separate
equipment schedules, as well as optimising the conventional
markup and drawing process between engineers and
draughtspersons. From a practical design perspective, the
best way to illustrate the advantages of BIM utilisation and to
depict a brief description and a real-life example of some of
the BIM stages, is given in Figure 2 to further elaborate on the
progression chart in Figure 1.
Two-dimensional (2D): When referring to 2D design
drawings, these can be easily interpreted into a plan or
sectional view (top or side view perpendicular to an object)
two-dimensional illustration of components and/or systems
(that is, length, width, and depth — two only). An example of a
simple 2D view of a hospitals theatre’s HVAC system is shown
in Figure 2.
Figure 2: A 2D theatre HVAC system design.
Three-dimensional (3D) project model: As the name
depicts, the design model’s system/component has three
dimensions (that is, length, width, and depth). This is best
illustrated from an isometric view of an object/system. An
example of a simple 3D view of a hospital theatre’s HVAC
system is shown in Figure 3.
Three-dimensional (3D) intelligent model: At this stage, the
3D model is further developed to contain vital component
and operational information. This information is used for
multidisciplinary information sharing, service integration,
accurate costing, comprehensive cost control, system
commissioning, and so on. Therefore, the 3D HVAC object/
system now contains design specification and operating
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Figure 3: A
3D theatre
HVAC system
design.
information as opposed to just a 3D object; hence, the model is
now ‘intelligent’. An example of a simple 3D intelligent model
view of a hospital theatre’s HVAC unit is shown in Figure 4.
Product reference
Manufacturer
Power (kW)
Height (mm)
Width (mm)
Depth (mm)
Area served
Asset identifier
Associated DB
Area served
HC-AHU-H-2
HC Heat Exchangers
6kW
1 200mm
2 800mm
900mm
Theatre room-01
RTPU-Theatre-01
MCP-T-01
Theatre complex
Figure 4: Intelligent 3D theatre HVAC unit design.
Four-dimensional (4D): The 4D element of the process
is annotating a time schedule/program to the 3D object/
system. This is to include a systematic approach for
installation of not just the object itself, but an integration
into the surrounding system and a coordinated schedule
of installation events with time allocation. This could also
be explained as a construction program integrated into
the intelligent 3D object. An example of the structural
progression of a warehouse facility’s development through
various stages is shown in Figures 5 and 6.
RACA Journal I January 2019
33