What is BIM?

WHAT IS BIM?

BIM, Building Information Model(ling), is defined by the US National Building Information Modelling Standard as ‘a digital representation of physical and functional characteristics of a facility’ is simply the digital form of a physical facility. Facility in this definition ranges from buildings and roads to geographical features like gullies, watersheds even towns and cities, etc.

It involves the creation of a digital model, containing all the parts of a facility, together with their properties (attributes like material, weight, soil conditions, etc.). The model can simulate the real life behaviour of the facility. With a single BIM model, there can be collaboration between different specialties (electrical, architectural, structural, etc.) who can work in their areas of expertise at the same time without having to wait for one another.

IS THERE A DIFFERENCE BETWEEN BIM AND CAD?

Yes there is! While CAD, Computer Aided Design, is a digital replication of a hand drafting of a structure, BIM displays all the information about the project digitally, including the costs, quantities of materials, dimensions of parts of the facility and more importantly is able to simulate how these factors affect each other as a single model. This unique feature shows how the work of one specialist affects the work of another. For example, if piping and electrical design carried out separately clash when updated to the main model, this will be easily resolved early in the life of the project by both specialists.

 HOW DOES IT WORK?

With BIM, a digital concept or model of the desired facility or an already existing facility is created (say, the alpha model), Copies of these are the given out to the different specialists (Architects, Structural Engineers, M and E, etc.). These experts work separately to fit in their unique components to the model, creating individual models. These changes in their models are then copied onto the alpha model and the changes effected on it. In this way, different specialists see the effects of their work on the overall model in real time as it affects the overall project.

BUT DIFFERENT SPECIALISTS WORK WITH DIFFERENT SOFTWARES, HOW IS IT POSSIBLE FOR ALL OF THEM TO WORK ON THE SAME MODEL?

With the help of Industry Foundation Classes (IFC) standards, information can be exchanged between the alpha model in a software and another software used by a specialist. Also software companies have arrangements with each other such that they can exchange data between their respective software. For example, between (Revit), which contains the alpha model and (Orion) used by structural engineers.

WHY USE BIM?

There are many benefits of BIM to design and construction experts, town planners, facility managers, etc. Some of these benefits include (but are not limited to):

ONE:  BIM serves both to visualise a facility and as a database for recording information developed and associated with the project. This will be helpful when future works are to be carried out on the facility.

TWO:  BIM is able to track the types and quantities of materials and used. Major building systems may be represented in distinct BIM models which can be integrated into a single alpha model.

THREE: With BIM, it is easy to find out conflicts early in the life of the project and resolve them.

FOUR:  It greatly saves time used in carrying out the project especially on an activity like drafting which is very time consuming, thereby saving costs.

FIVE:  It helps to reduce miscommunication between parties involved in a project due to its accuracy and ability to communicate effectively between them. It also reinforces understanding visually.

SIX:  Quantities and data can be automatically generated by the model, producing estimates and workflows much more quickly than conventional processes.

 WHO NEEDS TO LEARN ABOUT BIM AND WHY?

Anyone who is involved in shaping the built environment, from architects, engineers and planners to managers and clients and everyone in between.

It is necessary to learn BIM as it features prominently in the future of diverse fields ranging from engineering and architecture to project planning, project management and real estate.

Countries such as the UK already have a deadline of 2016 for the implementation of BIM Level 2 for all work on public sector work.

LEVELS OF BIM

There are four (4) levels of BIM which are described as follows:

 LEVEL 0 BIM: In this level of BIM, it simply means there is no collaboration. 2D CAD drafting is only utilized, mainly for Production Information. Output and distribution is via paper or electronic prints, or a mixture of both.

LEVEL 1 BIM: This combines a mixture of 3D CAD for concept work, and 2D for drafting of statutory approval documentation and production information. At this level, there is still no collaboration between different disciplines as each publishes and maintains its own data.

LEVEL 2 BIM: This involves collaborative working, though all parties own their own 3D CAD models, but not necessarily working on a single shared model. Collaboration comes about because there is exchange of design information between the different parties and is the crucial aspect of design at this level. With this, different parties can combine data to create an alpha BIM model. Common file formats such as IFC or COBie (Construction Operations Building Information Exchange).

LEVEL 3 BIM: seen as the holy grail of BIM, in this level, there is full collaboration between all disciplines by means of a single, shared project model which is held in a central repository. All parties can access and modify the same model, and the major benefit of this is that it removes the final layer of risk for conflicting information. This is also referred to as ‘Open BIM’.