3D rendering glossary
BIM (Building Information Modelling): guide
BIM (Building Information Modelling) is a working methodology that creates and manages a digital model of the building containing 3D geometry and information about each element: materials, dimensions, costs, phases and maintenance. All project stakeholders work on that shared model during design, construction and operation.
What sets BIM apart from a 3D model
A conventional 3D model describes shapes. A BIM model describes objects with meaning: a wall knows it is a wall, what layers it is made of, how high it is, which floor it belongs to and how much it costs. If you change a window in the model, the plans, elevations, sections and quantities are updated at the same time.
This is why BIM is not a piece of software, but a way of working. The software tools (Revit, ArchiCAD, Allplan, Tekla, Vectorworks) are the means to apply it, and the open IFC format allows information to be exchanged between them.
In practice: Render Fabrik is a 3D architectural rendering studio working with clients in Brazil and Europe, with a quote within 24 hours.
Key BIM components
- Information model: the geometric and alphanumeric database of the building.
- Level of development (LOD): indicates how much detail and reliability each element has, from a generic volume up to the object as built.
- Common data environment (CDE): the platform where models and documents are shared and versioned.
- BIM execution plan (BEP): a document that sets out roles, formats, naming conventions and deliverables.
- Standards: the ISO 19650 series governs information management in BIM projects.
BIM dimensions
| Dimension | What it adds | What it's for |
|---|---|---|
| 3D | Model geometry | Design, coordination, clash detection |
| 4D | Time | Phased construction planning and simulation |
| 5D | Cost | Quantities and budgets linked to the model |
| 6D | Sustainability | Energy analysis, life cycle, carbon footprint |
| 7D | Maintenance | Building management during operation (facility management) |
The numbering of 6D and 7D varies by country and author, but the underlying idea is the same: the model accumulates useful information throughout the building's entire life.
Benefits of BIM
In design
Architects and structural and building services engineers work on federated models. Clash detection finds collisions between a beam and a duct before they reach site, when correcting them is cheap.
On site
Quantities come from the model, which reduces budget errors. 4D planning helps organise phases, cranes and access. Documentation always reflects the latest version.
During operation
The owner receives a model with information on equipment, warranties and maintenance. In Spain, public procurement has been incorporating BIM requirements, and many private developers now require it on their projects.
Most widely used BIM software
| Software | Main use |
|---|---|
| Revit | Architecture, structures and MEP, widely used in large projects |
| ArchiCAD | Architecture, widely used by mid-sized studios |
| Allplan | Architecture and engineering, strong in structures and civil engineering |
| Tekla Structures | Steel and concrete structures with a high level of detail |
| Navisworks and Solibri | Coordination, model review and clash detection |
BIM and architectural visualisation
The BIM model is an excellent base for visualisation, but it is not directly a sales image. BIM models are designed to document and measure: they usually have simplified materials, generic furniture and no atmosphere. To obtain a photorealistic render, the model must be prepared:
- Export the useful geometry (for example, from Revit to 3ds Max or a real-time engine).
- Optimise meshes and remove elements that are not visible.
- Replace materials with realistic PBR textures.
- Add furniture, vegetation, people and surroundings.
- Light, frame and render.
The advantage is that the geometry is already exact, so the render faithfully reflects what will be built.
From BIM model to render in a visualisation studio
A visualisation studio frequently receives Revit or ArchiCAD models and turns them into 3D exterior images, interiors and videos for marketing. They can also feed an interactive virtual model, where buyers can browse homes and floor areas. If you are a developer or architect in Spain, see our Spain page.
Frequently asked questions
Is BIM a software program?
No. BIM is a methodology. Revit, ArchiCAD, Allplan or Tekla are software tools that allow you to work in BIM.
What is an IFC file?
IFC (Industry Foundation Classes) is an open, neutral format for exchanging BIM models between software from different vendors without losing element information.
Can renders be made from a BIM model?
Yes. The BIM model geometry provides the base; materials are then improved, surroundings and lighting are added, and it is rendered with engines such as V-Ray, Corona, Enscape or Twinmotion.
Is BIM mandatory in Spain?
Its requirement has grown in public procurement and depends on each tender and authority. In the private sector it is a decision for each developer, although it is becoming increasingly common.