What is BIM ? – 3D Architectural Modelling and BIM Software Explained

Inside a 3D virtual room

Architectural 3D Modelling is something that an Architect is familiar with, especially if the designer is well-versed with software like ArchiCAD. Engineering design also involves a lot of computer-based 3D modelling. When it comes to BIM, an acronym for Building Information Modelling, you have to imagine an architectural modelling platform that is open to other members of the construction team besides the architect. This means that anyone who is involved in the project, or anybody who has an interest in the project (for example, the local community) can access this platform to contribute their expertise, give suggestions or view the virtual building in its completed state.

To get a better understanding of BIM, you have to imagine a 3D virtual video game. There are many 3D virtual games that you can play on your PC or video console, for example Google Earth 6 Street View, Apollo 11, Dreadhalls, Dungeons & Dragons and The VOID.

Among 3D virtual games, there are single player games and multiplayer games (MMOGs).An architect working alone on a building model is like a single player game, and a building model where several members of the project team contribute to/or affect the design is like a multiplayer MMO game. The BIM environment involves multiple players (collaborators). However unlike in a MMORPG (Massively Multiplayer Online Role Playing Game), where users can assume any role, in a BIM environment you have actual specialists in various disciplines working on the model. For example, Architects work on the architectural aspects, Structural Engineers work on the structural aspects, Environmental Planners will assess the environmental conditions, Civil Engineers will design the drainage/water supply plan and Interior Designers will prescribe some suitable fittings, finishes, decorations and furniture. All these specialists are applying their specifications and prescriptions in relation to the 3D model. They have to find conflicts across the disciplinary specifications, and work out a solution. Compromises will be made and alternatives will be suggested before the final drawings are printed and issued to the Building Contractor. BIM allows the project team to foresee challenges and issues in the virtual model prior to the construction phase. On its own, BIM is a useful tool for performing feasibility studies across various fields on a centralized system.

The building contractor will assess the architectural model with a view of finding the most practical building methods gained from experience i.e. scaffolding, hoisting material, site access, logistics, movement and circulation.

The owner will log into the virtual platform to view the state of the virtual building in the planning and design stage. He or she can suggest changes to the aesthetics and layout of elements, as well as the quality and type of material used.

The Quantity Surveyor or Construction Cost Estimator will log into the virtual platform to extract quantities from the model, and consequently price the quantities to get a cost estimate at any stage of the design. This cost estimate will be used by the owner for financial planning and budgeting purposes.

If the client is a property developer, they will also be interested in the cost estimate. They will also want to check the virtual floor space of the model. BIM allows them to have a walkthrough in the 3D virtual project, checking the rooms, parking etc.

In the modern world, you cannot just build anywhere. You have to comply with local regulations and building codes. In some cases, the community needs to be consulted prior to building a structure in the area. An environmental impact assessment needs to be made. Therefore, in such a scenario where the community is involved, they are also stakeholders in the project. They will want to know how the building will affect the environment – will it disrupt the ecosystem, bring social problems, pollute the area, disturb the view or fit in well with existing dwellings? All these questions need to be answered and as such, the community representatives should have access to the virtual model to get a walkthrough.

Now that you have an idea what BIM is all about, you have to imagine all the relevant specifications by different specialists contained on a 3D Model object or item. When you click through to analyze that item, you should see the properties of that item, specification detail and preambles to trades (i.e. information on quality, workmanship, standards and methods of fixing, installation, construction, storage, treatment etc.)

When any of the above information or specifications is changed, the changes will be instantly applied to the model. On a 3D BIM model, changes are automatic, for example, when you change the door type, finish, material etc, the model will be updated. Dimensions are also automatically updated, resulting in new quantities which can be extracted by the Quantity Surveyor to prepare a cost estimate.

BIM is the fastest way of producing construction quantities. It automates the quantification process, saving the Estimator a lot of time. If the template is a BOQ, you can easily get Bills of Quantities and price them using your price list or costing system.

The following are BIM solutions that you can use to collaborate with construction teams ,project specialists, stakeholders and interested parties:

BIM Solutions

• ArchiCAD by GraphiSoft
• Revit by AutoDesk
• BIMsight by Tekla
• NBS BIM Toolkit – https://www.thenbs.com/services
• Edificius BIM Software by ACCA Software
• BIMx by GraphiSoft
• Aconex
• Vico Office by Trimble – 5D BIM for Estimating/ 3D BIM for Quantity Takeoff/4D BIM for Scheduling
• Vectorworks Architect