Scope your BIM project
before you invest.

BIM modeling is priced on effort, not a flat rate. Four inputs drive almost all of the cost: the modeled floor area, the number of model elements, the LOD (level of development) required, and how much coordination between disciplines is needed. As a working rule, design-stage modeling at LOD 300 runs roughly 1 hour per 250 sq ft for a typical mixed-use or office building, and that effort scales up sharply with LOD 350 and LOD 400. On top of effort sits the blended hourly rate, which varies widely by market — a US team bills far more per hour than an offshore one, even for identical scope. This tool multiplies effort by your selected market rate so the range reflects both what you build and who builds it.

In the US, most BIM scopes land somewhere between $0.60 and $4.00 per square foot of modeled area, with the spread driven almost entirely by LOD and complexity rather than geography. A straightforward LOD 200 massing model on a simple warehouse sits at the bottom of that range. An LOD 400 fabrication-ready model with full MEP coordination on a hospital or data centre sits at the top, and can exceed it. The most common mistake in estimating BIM cost per square foot is comparing two quotes without checking that both cover the same LOD and the same disciplines — an LOD 300 architectural-only model and an LOD 350 fully coordinated federated model are not comparable products, even at the same area.

LOD stands for Level of Development (sometimes called Level of Detail). It describes how much reliable information a model element carries, from conceptual through to fabrication-ready. LOD 100 is massing only. LOD 200 approximates size, shape and location. LOD 300 is precise enough for coordinated design and documentation, and is the default for most design-stage work. LOD 350 adds interfaces between disciplines so clashes are resolved at element level, which is what contractors typically need. LOD 400 is fabrication and assembly level, used for shop drawings. LOD 500 represents as-built verified conditions used for asset management. Choosing a higher LOD than the project needs is one of the most common sources of BIM budget overrun.

Team size is a function of total effort divided by programme duration, not of project value. A useful starting point is that one BIM coordinator covers roughly 3,000 to 5,000 hours of annual modeling and coordination output, and a discipline modeler produces roughly 1,400 to 1,800 productive model hours per year once holidays, meetings and rework are accounted for. That means a project needing 1,500 modelling hours delivered over 6 months typically requires a team of 2 to 3 people, not one. Compress the same scope into 3 months and the team roughly doubles. This tool derives the team from your area, element count, LOD, complexity and duration together.

Clash detection is where most of the financial return on BIM is realised. Independent industry studies consistently find that coordination performed in the model prevents a large share of site rework, and that rework on construction projects commonly consumes 5% or more of contract value. The value is not the clash report itself but the resolution rounds — federating models, identifying conflicts between structure, MEP and architecture, resolving them in a controlled sequence, then re-testing. Projects that skip structured coordination typically discover the same conflicts on site, where correcting them costs multiples more than in the model.

Scan to BIM converts a laser scan or point cloud of an existing building into a usable 3D model. It is worth the investment whenever accurate existing-condition data does not exist — renovations, fit-outs, heritage buildings, extensions, and any project where the original drawings are missing, incomplete or known to be out of date. Without a reliable survey, every downstream discipline works from assumptions, and those assumptions surface later as clashes, aborted fabrication and variations. Scan to BIM is normally priced separately from new-build modelling because point cloud processing is a distinct, labour-intensive workflow.

BIM return is best expressed as avoided cost rather than new revenue. The three measurable levers are reduced rework (conflicts resolved in the model instead of on site), faster coordination cycles (fewer review loops and less waiting between disciplines), and higher-quality tender and fabrication information (fewer assumption buffers added by bidders). This tool models those as a scenario range against your own inputs: your current workflow maturity, your priorities and your project complexity. It reports a 3-year savings scenario, a payback period and a net benefit. Treat the output as a planning scenario for internal discussion, not a guarantee — actual results depend heavily on how rigorously coordination is executed.

A BIM Execution Plan is a short governing document that defines the model uses, the LOD per element category, the file and naming conventions, the coordination cycle, the responsibility matrix and the deliverables schedule. On any project with more than one modelling party, the BEP is what prevents scope disputes — without it, each party assumes someone else is responsible for federating, for clash resolution and for as-built information. ISO 19650 formalises this as the BIM Execution Plan responding to an Exchange Information Requirements document. Even on smaller projects, a two-page BEP materially reduces the risk of rework and scope creep.

Both are valid, and the deciding factors are sustained pipeline volume and peak load. An in-house team makes sense when you have a predictable, continuous modelling demand large enough to keep staff utilised year-round; the trade-off is the fixed cost of salaries, software and training during quiet periods, plus recruitment difficulty in tight markets. Outsourcing makes sense when demand is variable, when you need to scale quickly for a single large project, or when you need specialist scopes such as scan to BIM or 4D sequencing that would be inefficient to staff in-house. Many firms run a hybrid: a small core in-house team for standards and client liaison, supplemented by external capacity for peak delivery. This calculator lets you compare both by switching the sourcing option.

Duration is governed by the project programme and the LOD, not by area alone. A typical sequence runs mobilisation and standards setup first, then model development, then federation and coordination rounds, then documentation and handover outputs. As a rule, model development occupies roughly the first 40% of the programme, coordination the middle 35%, and documentation and deliverables the final 25%. Compressing BIM delivery below the natural coordination rhythm is counterproductive — it reduces review rounds and pushes conflicts back onto site, which is exactly what BIM was engaged to prevent.

All BIM is 3D modeling, but not all 3D modeling is BIM. A 3D model is geometry. A BIM model is geometry plus structured, queryable information — each element carries its type, size, material, fire rating, cost data or asset identifiers, and those attributes can be scheduled, filtered and exported. That information layer is what allows a BIM model to produce door schedules, quantity takeoffs, COBie asset data and clash reports automatically. It is also why a BIM model takes longer to build than pure geometry: the value sits in the data attached to the geometry, not the shape itself.

A BIM model represents the project as designed. A digital twin represents the asset as it actually operates, fed by live or periodic data from sensors, meters or maintenance systems. The link between them is structured asset information — commonly delivered as COBie or a similar data schema — captured at handover and then maintained through operations. In practice, a digital twin is rarely a modelling exercise alone; it is an information management commitment that outlives the construction programme. For most projects, the realistic first step is delivering clean, structured as-built asset data at handover, since a twin cannot be built on unstructured information.

They overlap more than they conflict, and each suits a different context. ISO 19650 is the international framework for managing information across the asset lifecycle, and is increasingly the common language on cross-border and government work. NBIMS-US is the US national standard and appears frequently on federal and institutional projects, often alongside COBie asset data requirements. Australia and the UK commonly specify national BIM Execution Plan templates that respond to ISO 19650. If your project has a public-sector client, follow their stated requirement. If it does not, specifying ISO 19650 plus a project BEP is the safest default, because it is the most widely recognised and does not constrain your supply chain.