3D Modelling with AI · Construction Contractors Hub

Tim Fairley

8d • General discussion

3D Modelling with AI

Historically, 3D modelling has been difficult and technical.

You’d require a specialist BIM modeller and expensive software licenses.

The cost and expertise were prohibitive.

Now you can use AI and free tools to transform construction drawings into a 3D model.

Is it perfect? Can you do complex MEP co-ordination? No.

But we can build approximate models that open up a range of use cases that solve genuine construction problems.

This week I’m going to show you exactly how to do this and what I think the opportunities are. It will follow our usual structure of News, Inform, Work.

Here is a video explainer:https://www.youtube.com/watch?v=NvWioXGnTsc

News: Haiku 5.5 is worth a look

Anthropic released Haiku 5.5 on 7 October. It’s aimed at repetitive jobs such as summaries, document classification and quick lookups. Read the announcement.

What I found fascinating about this is Haiku 5.5 is actually a stronger model than Opus 4.7 which is only less than 6 months old. It suggests that the trend is the strong models will eventually get made cheap

Inform: Does BIM actually improve project performance?

A 2013 review of 35 construction project case studies found that 21 reported cost reduction or control benefits from BIM. Twelve reported time benefits. Read the study.

The evidence is mixed. A separate study of 93 US commercial projects found no statistically significant performance improvement after accounting for other project factors. Read the research.

My view: these tools always amplify the user's performance. A capable CM with BIM will outperform the same CM without it. A bad CM will not get a benefit from it. That’s why you see mixed outcomes.

Work: Turn your drawings into a 3D model

I used Codex desktop, Blender, Bonsai and MCP for Blender. Blender and Bonsai are free. AI access and usage are separate.

Install Blender and Bonsai. In Blender, go to Edit → Preferences → Get Extensions. Allow online access, then search for and install Bonsai. Installation guide.
Connect Codex. Ask it to install MCP for Blender and configure the connection. Restart both apps.
Check the connection. In Blender’s 3D viewport, press N → MCP for Blender. Start the server if needed.
Review your drawings. Open their folder in Codex. Ask for a concise modelling plan, including missing information and assumptions.
Build and check. Approve the plan. Ask for separate element groups you can hide and show. Compare the result with the drawings.
Save both files: the Blender project (.blend) and IFC model (.ifc).

Treat the result as an approximate model. AI can misread dimensions and omit elements. I would not rely on it for detailed MEP coordination.

Where I see it being useful

Reading drawings: Hide the roof and cladding to understand how the foundations, columns and beams fit together.
Stakeholder communication: Walk clients and subcontractors through design options and construction stages.
Dynamic planning: Add programme links to compare sequences, crane positions, deliveries and available space over time.
Unified WBS: A further step is to connect model elements, activities, quantities, resources, costs and progress through common work packages. This needs additional data and maintained links.

Get the free setup skill in Contractors Hub.

It guides you through the Windows setup I used.

You can also watch the full video walkthrough.

Start with a small drawing set and one question you want the model to help answer. Reply and let me know what you try.

Thanks,

Tim

P.S. Want to work with me directly? See how we can help.

P.P.S. For a step-by-step AI implementation roadmap and pre-built workflows, join ContractorOS (paid).

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3D Modelling with AI