La mera tenencia.

Discipline-specific model constructions in the Seawater Chamber case study include architectural, hydraulic and lighting models. After the architectural model was constructed, converted and uploaded to EDMmodelServer™ in the repository, the architectural model was made available for download and was used as a reference model for constructing the hydraulic model and the lighting model. Different applications are used to construct these discipline-specific models, i.e. ArchiCAD for constructing the architectural model and DDS- CAD for constructing the hydraulic and lighting models. After the hydraulic and lighting models were completed, they were checked-in to EDMmodelServer™ and merged with the architectural model to develop the integrated BIM model. The building information of each discipline-specific model became sharable with other discipline-specific models for project collaboration. Design review of the construction for different discipline-specific models provides data verification to ensure the accuracy of the BIM model. Figure 3.2 illustrates the above model integration process.

54 Figure 3.2 Discipline-specific model integration

Architectural Model a. Model construction

Based on the original design drawings, and a partial 3D model provided by the client as shown in shown in Figure 3.3, the architectural model (Figure 3.4) for the case study was constructed using ArchiCAD. The architectural model captured more precise building information for the Seawater Chamber and included surrounding spaces to illustrate spatial relationships. This model was then converted into IFC format and uploaded into EDMmodelServer™, as shown in Figure 3.5.

55 Figure 3.4 Developed architectural model for the Seawater Chamber case study modelled in ArchiCAD

Figure 3.5 The architectural model of the Seawater Chamber uploaded in EDMmodelServer™

b. Object properties

ArchiCAD is an object-orientated 3D modelling application which provides different functions for defining object properties. The examples of these properties are shown in Figures 3.6 and 3.7 for a slab object, a wall object and a door object respectively. In these two figures,

56 through Listing and Labelling, various calculations of building information can be performed, for instance,

• ID can be used to track elements for quantity calculations.

• Link Properties enable the use of different criteria for calculations. • By Criteria assigns variables to special conditions, e.g. element type.

• Matching Priorities displays the property items whose criteria match the current attribute set.

The information in Listing and Labelling can also be used to relate to the linked and external information for further cost estimation and facility management

57 Figure 3.7 Object properties for a door object

The Seawater Chamber architectural model can be converted directly into IFC format. Figure 3.8 shows the building object hierarchy of the architectural model produced for the case study. The Model Tree on the top left-hand-side of the figure shows different object categories of the model. The bottom left-hand-side of the figure shows detailed information of the object if it is selected. The 3D view of the architectural model is shown on the right-hand- side of the figure.

58 Figure 3.8 The Seawater Chamber architectural model in Solibri Model Viewer

Hydraulic model a. Model construction

The Seawater Chamber hydraulic model was developed based on the original design drawings as shown in Figures 3.1 and 3.9. The architectural model downloaded from EDMmodelServer™ was used a reference model. The model was constructed using Data Design System (DDS-CAD). DDS-CAD is a CAD solution in the construction industry for the design and documentation of electrical, HVAC and plumbing systems. It is capable of object- based modelling of facilities. With support for DXF/DWG export and IFC integration, DDS- CAD provides the basis for integrated multi-disciplinary planning and design. Figure 3.10 shows the developed Seawater Chamber hydraulic model uploaded in EDMmodelServer™.

59 Figure 3.9 Design drawing of the hydraulic system and chemical dosing equipment of the Seawater

Chamber, provided by the client

Figure 3.10 The hydraulic model of the Seawater Chamber uploaded in EDMmodelServer™

b. Object properties

The hydraulic model of Seawater Chamber is constructed using DDS-CAD. DDS-CAD for hydraulic and HVAC provides functions for creating and modifying different object properties. Figure 3.11 shows an example of the settings of an air handler unit (AHU) in a HVAC system.

60 Figure 3.11 Property settings of an air handler unit (AHU) in DDS-CAD (image taken from DDS HVAC

Partner Training Guide)

Figure 3.11 Property settings of an air handler unit (AHU) in DDS-CAD (image taken from DDS HVAC Partner Training Guide)

Figure 3.12 shows different object categories of the Seawater Chamber hydraulic model including flow terminal, pipe, pipe fitting, pump and valve (top left-hand-side of the figure), and their 3D view (right-hand-side of the figure).

Figure 3.12 Seawater Chamber hydraulic model in Solibri Model Viewer

DDS has both modelling and calculation tools. By providing parameter values of objects, the model can be applied for hydraulic energy simulation. However, the hydraulic model should be a closed system which means that every object within the model needs to be connected with other objects.

61 Lighting model

a. Model construction

The development of the Seawater Chamber lighting model was based on the architectural model as the reference, downloaded from EDMmodelServer™. Due to a lack of detailed information of the lighting system, this model was only a simplified model. Nevertheless it captures key elements of a lighting model and is suitable for demonstration purposes in the case study. The model is developed using Data Design System (DDS-CAD Electrical). Figure 3.13 shows the developed Seawater Chamber lighting model as uploaded in EDMmodelServer™.

Figure 3.13 The lighting model of Seawater Chamber uploaded in EDMmodelServer™

b. Object properties

Similar to DDS-CAD for hydraulic and HVAC, DDS-CAD Electrical also provides functions for creating and modifying different object properties. Figure 3.14 is an example for inserting a light object into the lighting model.

62 Figure 3.14 Property settings of light fittings to be inserted into DDS-CAD

Figure 3.15 shows different object categories of the Seawater Chamber lighting model including cable carrier, cable carrier fitting, duct fitting, light fitting, lighting fixture and switching device (top left-hand-side of the figure). Their 3D view is shown on the right-hand- side of the figure.

Figure 3.15 The seawater Chamber lighting model in Solibri Model Viewer

In addition, DDS Electrical provides a built-in light calculation function based on the simple lumen method of calculation. For light calculation, different information and parameters are needed including room data, article data and placing of articles (Figure 3.16).

63 Figure 3.16 Different parameter values needed for light calculation, as supported in DDS-CAD