BIM modeling services
What Is BIM? A Plain-English Guide for Small Firms and Contractors
Building Information Modelling, or BIM, is often presented as something only large firms need. In reality, smaller architects, contractors and specialist subcontractors can benefit too, as long as they understand what BIM is, what it is not, and when it is worth the effort. This guide explains BIM in plain English.
BIM in one sentence
BIM is a way of designing and managing a building using an intelligent 3D model, where each element (a wall, a door, a slab, a duct) carries information such as size, material, cost and performance, rather than just being lines on a drawing.
In traditional 2D CAD, a wall is two parallel lines. In BIM, a wall is an object with a type, height, layers, fire rating and more. Plans, sections, elevations and schedules are all generated from the same model, so a change in one place updates everywhere.
Common BIM software
The most widely used BIM authoring tool in many markets is Autodesk Revit. Others include ArchiCAD, Tekla Structures for steel and concrete, and various MEP tools. Models are often exchanged in the open IFC format, maintained by buildingSMART International, which allows different software to share data.
Levels of development (LOD)
Models are built to different levels of detail depending on the stage of the project. A widely referenced framework is the LOD Specification by BIMForum, which describes increasing levels from conceptual massing to fabrication-ready elements. Agreeing the LOD upfront prevents over-modelling (and overpaying) or under-modelling.
BIM standards by country
- UK: BIM processes are guided by the ISO 19650 series, and the UK BIM Framework provides practical guidance.
- USA: The National BIM Standard-United States (NBIMS-US) is commonly referenced.
- Canada: Organisations such as buildingSMART Canada publish guidance.
- UAE: Dubai Municipality has issued BIM requirements for certain building types and sizes.
Requirements change over time, so always confirm the current rules for your project.
Benefits for small firms
Fewer coordination errors. Clash detection between architecture, structure and MEP catches problems before site.
Automatic schedules. Door, window, finishes and area schedules update with the model.
Better visualisation. A BIM model can be rendered or walked through, helping clients understand the design.
Quantity take-off. Estimators can extract quantities directly from the model.
Competitive edge. Some clients and tenders now require BIM deliverables.
When 2D CAD is still enough
BIM is not always necessary. For a single shop drawing, a small residential extension, or a stone cutting drawing, 2D AutoCAD is often faster and cheaper. Many projects use a hybrid approach: a BIM model for coordination and design, with detailed 2D shop drawings for fabrication.
For marble and stone work in particular, fabricators usually need precise 2D piece drawings and cutting lists, even when the overall project is in BIM.
How to start with BIM as a small firm
- Start with one pilot project rather than switching everything at once.
- Build a small library of families or objects you use repeatedly.
- Agree a simple naming and LOD convention.
- Consider outsourcing modelling for peak periods while your team learns.
What to ask a BIM freelancer
- Which software and version will be used?
- What LOD and which elements will be modelled?
- Will you deliver native files, IFC, or both?
- How will sheets and schedules be set up?
- How are revisions handled?
Summary
BIM is a powerful approach that can benefit firms of every size, but it should be applied where it adds value. If you need help with BIM modelling or want 2D AutoCAD drafting to complement a BIM workflow, reach me on Fiverr or email mxhoaib0@gmail.com.