BIM Dimensions: What is 3D, 4D, 5D, 6D and 7D?
Lightbulb with Earth inside

How many BIM dimensions does it take to change a light bulb? Up to seven, according to the boffins. OK that’s not much of a punchline, we’ll admit – just another example of the unstoppable progress of Building Information Modelling.

You’d be forgiven for assuming that anything beyond three dimensions was within the realms of science fiction, but no, we’re not entering The Twilight Zone. In the wonderful world of BIM, 3D, 4D, 5D, 6D and 7D can be broken down like this:

3D = space

4D = time

5D = cost

6D = sustainability

7D = facility management

Clear as the Great Barrier Reef after a cyclone in Cairns? Fear not, dear reader. Don a wetsuit, strap on your scuba gear and join us on Drawable’s deep dive into BIM Dimensions…

Birth of BIM

Back in the day, a draftsman would be hired to draw up two-dimensional plans for a construction project using paper on a drawing board – hence the phrase ‘back to the drawing board’ when things go pear-shaped. Computer-aided design software like AutoCAD started to take over in the 1980s, and drafters traded their pencils and protractors for digital drawings. Fast-forward to the 21st century, modern software called Revit allows us to add the third dimension and build digital models.

What is 3D?

“That’s easy!” we hear you say. “It’s length and depth and breadth.” Yes, it is – and much more.

In BIM terms, 3D is a shared information model that helps all stakeholders (architects, engineers, builders, manufacturers, tradies etc) visualise the project in three dimensions – the space – and collaborate before the ground is even broken. This collaboration might involve checking existing conditions with 3D laser scanning and updating the model according to those scans; plus generating animations, renderings and walkthroughs.

So if we return to our lame lightbulb joke, 3D BIM shows where the light fitting (the model element) for said bulb is situated within the project model.

What is 4D?

This is where time comes into the picture. 4D BIM tracks what happens to the building program in the instance of project changes, allowing stakeholders to visualise and extract data regarding the progress of the project.

Continuing our light-bulb example, this might include information on lead time to have a purchased light fitting delivered, or have a bespoke light fitting manufactured. This is of course extremely valuable for accurate planning and manpower coordination – i.e.  electrical contractors can easily find out when they need to schedule their crew to install the light fitting once it’s available.

What is 5D?

Now onto cost. Estimators will be stoked to learn that they can throw their clicker counters in the bin – no more thumb blisters! 5D BIM makes their job a shed-load easier by turning take-offs into an automated process. That’s right, the model itself can tally up how many of those specific light fittings are needed and how much they’ll set you back. Boo-yah.

What’s more, 5D BIM can adapt according to how the project is progressing or, if for some reason the scope of works changes, evaluate and adjust costs to suit. All of which makes the project more efficient and cost-effective.

What is 6D?

When 13-year-old kids stop Snapchatting and take to the streets protesting climate change inaction, you know us grown-ups have to take sustainability seriously. This is where 6D BIM comes in as a valuable tool in the procurement process.

6D is the dimension that helps analyse the energy consumption of elements in the model, so you can perform accurate simulations showing exactly how efficient your chosen light fitting will be and how long it should last. This allows for seriously informed decision-making for sustainability.

And with the pollies making a right pig’s ear of reducing carbon emissions, every bit matters. Remember, you’ve got Sienna and Lachlan to answer to…

What is 7D?

Admittedly this is crystal ball territory, but the BIM experts envisage that this dimension will encompass facility management throughout the development’s life cycle – from initial design right through to demolition.

The plan with 7D BIM is that facility managers will be able to use the model as a tool in the maintenance and operation of the site moving forward. It will be possible for them to track and extract super-useful information about elements in the model.

Back to our light fitting example, they can find out how to change that light bulb by accessing the user manual from within the model. Plus if it breaks the warranty data is there too, as well as supplier information that tells them where to source a replacement. There’s also the potential for the model to store intel on how to safely dispose of and/or recycle that light fitting when it reaches the end of its useful life. Pretty amazing, eh?

There you have it, Drawable’s no-nonsense take on the 7 Dimensions of BIM. A word of warning, though: all the above represents a ‘perfect world’ scenario where the effectiveness of the dimensions completely depends on the quality of the model. That’s why it’s so important for all stakeholders – yes that includes you, Mr ‘It’ll Never Catch On’ – to be totally on board with BIM right from inception of the project.

Still not convinced? We’re happy to have a chat and answer any questions you have about all things BIM. Just get in touch with the expert Building Information Modellers at Drawable and you might have a light-bulb moment.