BIM is an abbreviation used to describe either the Product, Building Information Model, or the process Building Information Modeling. Many believe that BIM is the same as 3D, but this is not quite right. 3D is just one possible report from a BIM. 2D may be another and a door schedule may be a third. BIM is not only 3D, but building information related to intelligent objects that know what they are and have relations to other objects, classifications and groups. You can "ask" a BIM and get answers ...
That said, of course, the 3D representation is an important skeleton that gives all building information xyz coordinates and thus all information got “a location”. This is a skeleton that StreamBIM and other software tools can add additional information, such as discrepancy, photo documentation, etc.
Building information modeling as the design method and process is not complicated, and has become the industry standard as one sees both successful and less successful examples of. In many cases, there are still 2D drawings that are main supply and contractual production bases. In many cases, this has led to modeling to produce drawings, but we see that this has a cost in terms of model quality. If the models are also used for interdisciplinary crash control and coordination, it obviously gives positive effects, because drawings from coordinated 3D models provide constructable drawings and are therefore less error prone. However, the potential is greater than that.
The open BIM standards from buildingSMART make it possible to transport and reuse data between phases, processes and associated applications. For Rendra's StreamBIM, this means, among other things, that we can receive projected models regardless of the design tools and present this so that the production base is available on handheld devices also on site.
Get off on the right foot!
Characteristics of a successful BIM project is that they have had a clear understanding of what to use BIM for in “this project". In most BIM projects we see successful clash detection for interdisciplinary (geometric) coordination. Should this be achieved, the designers must operate with the same model origin and coordinate system. A test of this should be a natural part of design startup/initiation. We recommend that all design groups define a simple and interdisciplinary model, including Architecture, structural design, power supply, plumbing and ventilation, and test that the different domain models geometrically are located at “the same spot”.
A coordinated origin is not only important for clash detection/3D coordination, but important for all downstream processes and applications where it is naturally used an interdisciplinary / composite model such as StreamBIM.
Another rule of thumb is to have good structure and rules for naming objects. This does not seem so important in an early phase of the project, but you will save a lot of plunder and time subsequent phases by making objects and models readable for both humans and software. BIM projects in open formats advocate reusing data across phases and processes rather than reproducing, and readability is thus an important aspect.
Unique naming will include both type entries on building elements / components, including space names and numbers and further groupings of objects such as systems and zones (groups of rooms). Some objects are important to identify the individual instances of, and these are usually objects to be operated in building automation systems (BAS). We talk primarily about components within technical domains (MEP), but doors (and hatches) may also have such needs. Owners/clients often require the use of Interdisciplinary ID’s (e.g. according to COBie), but this is a general requirement that applies to all buildings of a certain size.
We want to emphasize the need for good type designations that are important in many downstream processes. For example, for quantity take-off/cost estimation, but also for an installer, it is important that it is clear which product he picks up of the box when he sees a given type ID (on the drawing) or object property in StreamBIM.
Model structure/organize files
How to structure the different domain models in projects depends both on the size of the project and BIM authoring tools in use. Particularly within MEP, large models can involve a lot of waiting if everything is to be modeled in one model and all system-relations are established (best practice). How files are organized and exported to ifc is relevant in StreamBIM for how to view the 3D model, as the 3D interface is organized in “layers”. A "layer" will typically be within a domain. E.g., ARCH, MECH, ELEC, STRUC etc., and this can be switched on and off or highlighted in StreamBIM. A layer can consist of one or more files, so if you have exported pipe and ventilation in the same file, you cannot "turn off or highlight" just ventilation. If needed, this must be exported as two ifc files. If you want to see the sprinkler system, this must also be a separate file. However, if you have multiple files within a domain, it is easy to merge this into one layer.
BIM for a purpose
Once you have decided to use BIM in your project, requirements (established in a BIM guide) will follow these objectives. So have an understanding of what you are going to use BIM for and which business processes you can utilize BIM.
E.g. if you want to use the models for quantity take-off and costing, you need a different dataset than if you are going to use it for energy simulations. With dataset, we refer to attributes (e.g. naming conventions, ID’s, etc), properties and Level of Detail.
E.g. quantities can be derived from BIM in two different ways. You can either export this as properties to objects, or you can “analyze” the objects (e.g. by triangulating around them). If you choose the analyze-approach you need a tool/software that can do this for you like Solibri Model Checker or equivalent.
StreamBIM is a tool that typically reads the properties of the objects and presents this in an intuitive way for the users. If you want quantities to appear in StreamBIM, quantities must be be exported to the ifc file as properties. It is well-defined how to export this to ifc, so-called "BaseQuantities", which specifies how BIM authoring tools export length, area, diameter, etc. In most CAD / BIM tools, this is a simple setting when exporting to ifc. For example, you get an option to "Include base quantities".
Building information from other sources in StreamBIM
We have previously highlighted the importance of good naming of objects, for example using interdisciplinary labeling/ID-tags. These may be identifiers that are also used in other software and databases. Why do we mention this?
Because if StreamBIM finds an identifier in the models that can be used for querying other sources/databases, we can present other web clients in StreamBIM interface. In other words, you can see relevant data about an object (building, floor, room, component, system, etc.) even if the data is not in StreamBIM or in ifc. You simply do a look up and get answers from external sources.
BIM is not complicated, and with StreamBIM it has never been easier. With some pretty few rules of thumb when you start your project, it's only upload models and drive.
- The same shared origin for all domain models
- Good and structured naming conventions (focus on type-names from the very beginning)
- Define what to use the models in the project - What's going into the model is defined by purpose. You need BIM for a purpose!
It's not rocket science, it’s simple - good luck!