BIM Hub

What is BIM and why it matters for Indian civil projects

BIM is not a 3D model — that's a common misunderstanding. BIM is a structured *process* for producing, exchanging, and operating information about a built asset throughout its lifecycle — from brief to decommissioning. The 3D model is one output; the *information* inside it (geometry, properties, relationships, status) is the value.

For Indian engineers, BIM matters for three reasons.

Large infrastructure projects increasingly demand BIM: the Delhi-Meerut RRTS (NCRTC) is the most prominent verified Indian BIM adoption — NCRTC's BIM Execution Plan cites ISO 19650-2 explicitly. Other large projects (select metro stations, airport expansions, multi-disciplinary coordinated projects) often require BIM for coordination and clash detection even if not fully ISO 19650-compliant. If you work on such projects, you'll be asked for BEP documents, CDE workflow, and IFC deliverables.

International consultants bring BIM standards: firms like AECOM, Arup, Jacobs, Mott MacDonald — operating in India — run their India projects on the same ISO 19650 process they use globally. Indian firms subcontracting to international consultants must produce BIM deliverables per the consultant's BEP, which typically cites ISO 19650.

Standardised information reduces disputes: construction disputes in India often arise from ambiguous drawings, outdated documents, and missing information. A BIM-enabled project with a proper CDE (Common Data Environment) and structured information exchange reduces this ambiguity — every document has a status (Work in Progress / Shared / Published / Archived), a revision, and a responsible party. It doesn't eliminate disputes, but it shrinks them.

Importantly, there is no Indian Standard dedicated to BIM as of 2026. BIS has not published any IS code on Building Information Modelling. Indian projects reference the international ISO 19650 series directly. Anyone claiming that IS 17765 is a BIM standard is mistaken — IS 17765:2022 is a Medical Informatics standard on personal health data, unrelated to BIM.

ISO 19650 series — the core BIM standards

ISO 19650 is the international standard for information management using Building Information Modelling. Published between 2018 and 2022, it is organised in five parts that collectively define the BIM process.

[ISO 19650-1:2018](/code/ISO-19650-1-2018) — *Concepts and principles*. The foundation document. Defines vocabulary (OIR, AIR, PIR, EIR, Information Container, Information Model, Federated Model), core principles (appointment chain, common data environment, resolution of information requirements), and the overall BIM process framework. Read this first before diving into delivery or operational phases. Approx 38 pages.

[ISO 19650-2:2018](/code/ISO-19650-2-2018) — *Delivery phase of the assets*. The operational standard for design and construction. Defines the 8-activity process for each information exchange: (A) assessment and need, (B) invitation to tender, (C) tender response, (D) appointment, (E) mobilization, (F) collaborative production of information, (G) information model delivery, (H) project close-out. Also defines the BEP (BIM Execution Plan) structure, the MIDP (Master Information Delivery Plan), and TIDP (Task Information Delivery Plan).

[ISO 19650-3:2020](/code/ISO-19650-3-2020) — *Operational phase of the assets*. For facility management post-handover. Defines the transition from Project Information Model (PIM) to Asset Information Model (AIM), ongoing information management during operations, and the trigger events that cause information updates (renovation, retrofit, decommissioning).

[ISO 19650-4:2022](/code/ISO-19650-4-2022) — *Information exchange*. Detailed specifications for how information containers move between parties — acceptance criteria, verification, metadata requirements. Complements ISO 19650-2.

[ISO 19650-5:2020](/code/ISO-19650-5-2020) — *Security-minded approach to information management*. For defence, critical infrastructure, and sensitive projects. Information classification, access control, secure exchange protocols. Referenced by NCRTC and other security-sensitive Indian projects.

IFC — the open BIM data format

IFC (Industry Foundation Classes) is the open, vendor-neutral data format for BIM information exchange — standardised as [ISO 16739-1:2024](/code/ISO-16739-1-2024) with the current IFC 4.3 ADD2 schema. Unlike proprietary formats (Revit RVT, ArchiCAD PLN, Tekla TEK), IFC is an open specification that any BIM software can read and write.

For building projects (residential, commercial, institutional), IFC 4 (4.0) has been widely supported since 2013 and remains the practical default. All major BIM platforms — Autodesk Revit, Graphisoft ArchiCAD, Bentley AECOsim, Vectorworks, Tekla — produce IFC 4 reliably.

For infrastructure projects — bridges, roads, railways, tunnels, marine works, water networks — use IFC 4.3 ADD2 or later. IFC versions prior to 4.3 cannot represent these domain entities — a bridge abutment in IFC 4 becomes a generic 'building element proxy' with no domain semantics. IFC 4.3 adds native entities: IfcBridge, IfcBridgePart, IfcRail, IfcTrackElement, IfcRoad, IfcRoadway, IfcMarineStructure, IfcMarinePart, IfcBuiltSystem for utilities. If your project is metro, RRTS, highway, or dam — IFC 4.3 is non-negotiable.

Open vs closed BIM: *Closed BIM* means the project runs inside a single vendor's ecosystem (everyone uses Revit + Revit native files). *Open BIM* means parties collaborate using IFC exchanges regardless of the authoring tool. ISO 19650 doesn't mandate open BIM, but many sophisticated clients (NCRTC, major Indian PMCs on international projects) require IFC deliverables alongside native files for long-term information preservation.

LOD, LOIN, and information-need frameworks

A persistent confusion in BIM practice: how much detail should a model have at each stage? Two frameworks exist — LOD (older, more common in India) and LOIN (newer, more precise).

LOD (Level of Development) originates in the American Institute of Architects (AIA G202-2013 and later BIMForum LOD Specification annual updates). LOD bundles *geometric detail* and *non-geometric information* into a single number. Common levels: LOD 100 (conceptual massing — symbolic representation, cost per sqft), LOD 200 (approximate geometry with generic properties — RFP stage), LOD 300 (precise geometry with specified properties — design development), LOD 350 (LOD 300 plus coordination between systems), LOD 400 (fabrication-ready geometry and details), LOD 500 (as-built, verified).

LOD is simple and widely understood in Indian BIM tenders — most Indian LOD specifications use LOD 300 as the BIM deliverable baseline for design and LOD 350 for coordination.

LOIN (Level of Information Need) was published in [BS EN ISO 7817-1:2024](/code/BS-EN-ISO-7817-1-2024) (replacing BS EN 17412-1:2020). LOIN splits what LOD bundles into three independent dimensions: G (Geometric) — how geometrically detailed, from G1 (symbolic) to G5 (precise fabrication); A (Alphanumerical) — what properties are required, defined by property set and data templates; D (Documentation) — what auxiliary documents are required (datasheets, certificates, calculations).

LOIN is more precise than LOD — instead of saying 'LOD 300', you specify 'G3 + A(structural.properties.v2) + D(datasheet + calculation)' for beams. But LOIN adoption in Indian projects is still slow; most Indian BIM contracts use LOD. If you work on international projects (especially UK or Continental European projects), expect LOIN notation.

Common Data Environment (CDE) — the backbone of ISO 19650

A CDE (Common Data Environment) is the single trusted location where all project information lives during BIM-enabled delivery and operation. ISO 19650-2 mandates a CDE for every BIM project. Without a CDE, there is no ISO 19650 compliance.

Four states for every information container in a CDE:

WIP (Work in Progress): the container is being actively authored. Only the author and their immediate team have access. Not suitable for coordination or client review.

Shared: the container is ready for coordination with other parties. Other disciplines can reference it but cannot edit. This is where clash detection happens.

Published: the container has been approved by the appointing party (client) and is the current authoritative version. Payments and formal decisions are based on published containers.

Archived: the container has been superseded by a newer version but is retained for audit trail. Cannot be edited or reused but can be referenced.

Common CDE platforms used in India: Autodesk Construction Cloud (formerly BIM 360), Aconex (by Oracle), Bentley ProjectWise, Asite, Trimble Connect, Procore. Each has its own approach to implementing the four CDE states, folder structure, and approval workflow — but any ISO 19650-compliant CDE supports the same process.

For smaller Indian projects without a commercial CDE budget, a disciplined SharePoint or Google Drive folder structure (with a WIP / Shared / Published / Archived folder convention, metadata spreadsheet, and approval log) can meet the spirit of ISO 19650 — though it lacks the automated approval workflow of purpose-built CDEs.

BEP and EIR — the BIM contract documents

Two documents govern the information management on any ISO 19650-compliant project.

EIR (Exchange Information Requirements) is issued by the appointing party (client) in the tender. It specifies *what information the client needs, when, and in what format*. An EIR typically contains: project information model purpose, information deliverables (drawings, schedules, models, reports), LOD/LOIN requirements per element, IFC and native format requirements, CDE requirements, information security requirements (if ISO 19650-5 applies), and the BIM execution requirements contractors must address in their BEP response.

In Indian practice, the EIR is often bundled into the broader RFP document rather than being a standalone file — but the ISO 19650 expectation is a dedicated EIR document.

BEP (BIM Execution Plan) is the appointed party's (contractor's or consultant's) *response* to the EIR. It says 'HERE IS HOW I WILL MEET YOUR INFORMATION REQUIREMENTS'. There are two BEPs:

Pre-appointment BEP — part of the tender response. Proposes the team, the software tools, the process approach, the CDE selection. Used by the client to evaluate BIM capability during tender evaluation.

Post-appointment BEP — finalised after contract award, incorporating any clarifications and commitments from the tender. This is the live contract document governing information management for the duration of the appointment. Reviewed and updated at project milestones.

A well-structured BEP typically runs 40-80 pages and covers: appointment chain (who answers to whom), detailed team roles (Information Manager, BIM Lead, BIM Coordinators per discipline, BIM Modellers), tool stack, exchange schedules (MIDP), TIDPs per task team, CDE setup, approval workflows, IFC export protocols, model federation strategy, QA procedures, and security measures.

InfraLens's BIM Hub has template BEP and EIR structures that can be adapted to your project — search 'BEP template' or 'EIR template' in the handbook.

BIM in India — verified facts, unverified claims

BIM adoption claims in India are frequently exaggerated in marketing material and in trade press. InfraLens takes a verified-facts-only approach — we list what can be sourced and explicitly call out what cannot.

Verified: NCRTC (Delhi-Meerut RRTS / Namo Bharat) runs on an ISO 19650-aligned BIM process. The NCRTC BEP and related BIM documentation are sourced from NCRTC tender documents and project reports. This is arguably the most sophisticated BIM implementation on an Indian public project as of 2026.

Verified: Select metro rail projects — Delhi Metro Phase IV, Mumbai Metro Line 3, Bengaluru Metro Phase II — have used BIM for tunnel coordination and station clash detection, primarily driven by their international DPR consultants.

Partially verified: CPWD has published BIM adoption guidelines in internal documents, and a few CPWD projects (smart city campuses, specific public buildings) have required BIM. However, there is no CPWD-wide BIM mandate with an enforcement timeline — contrary to some trade-press claims.

Partially verified: NHAI has issued technical circulars mentioning 3D visualisation and BIM for specific highway projects, but there is no NHAI-wide BIM mandate as of 2026.

Unverified: Claims of a 'National BIM Mission' by the Ministry of Housing and Urban Affairs have circulated in industry press since 2019 but no formal mission document or launch has been verified.

Not a standard: IS 17765:2022 is sometimes misquoted as 'the Indian BIM standard'. It is not. IS 17765 is titled 'Health informatics — Personal health data generated on a daily basis' and is maintained by the BIS Medical Informatics sectional committee (MHD 17). It has no relationship to BIM or construction.

If you find a primary-source Indian government BIM circular that we haven't listed, email info@infralens.in — we'll verify and add it.

Frequently Asked Questions

12 common questions about this topic, answered by civil engineers.

Related resources on InfraLens