NBS National BIM Library

• Free UK-wide BIM object library
• NBS BIM Object Standard published
• Objects linked to specification

Why Revit and the Multi-Platform Approach

The National BIM Library was never a single-platform product, but Revit is the format most designers associate with it, and the reasons are worth setting out because they explain how BIM content libraries are built.

Objects have to live inside the authoring tool

A BIM object is only useful if it behaves correctly once placed: hosting properly in a wall, scheduling into the right category, flexing where it should flex and holding its data where the software expects to find it. That makes authoring native content unavoidable. A neutral geometry exchange such as IFC preserves shape and some data but not the parametric behaviour that makes an object worth using, so the library published native families alongside other formats rather than relying on translation.

Revit's market position in the UK

By the time the library launched, the UK government's push toward BIM Level 2 was driving adoption across the public sector, and Autodesk Revit held the largest share of UK architectural and building services modelling. A national library that did not serve Revit well would not have been used, whatever its merits.

Plug-in delivery rather than file download

Serving content through a free plug-in inside the authoring tool, rather than as a directory of downloadable files, is a deliberate design choice. It removes the manual step of finding, downloading, saving and loading a family, keeps objects current, and lets the placement action also carry information into the specification.

Platform neutrality as policy

Support for Bentley, Tekla and ArchiCAD alongside Autodesk was a requirement of the library's national role rather than a technical nicety. A library published by an RIBA-owned body, in a market with a government BIM mandate, could not be seen to endorse a single vendor.

No shared definition of a good object

The central problem the library set out to solve was that the industry had no agreed answer to what a BIM object should contain. Without that, every practice applied its own rules and no manufacturer could author content confidently.

Model bloat and performance

Manufacturer content authored without restraint on geometric detail can make a federated model unusable. Deciding how much geometry an object actually needs, and enforcing it through a standard, was a real technical constraint rather than a stylistic preference.

Bridging concept design and product selection

Designers need to model before they specify. A library that only offered branded products would have forced premature product decisions, which is why the generic layer was necessary and why the two sets had to be interchangeable.

Serving four authoring platforms

Authoring and maintaining equivalent content across Autodesk, Bentley, Tekla and ArchiCAD multiplies the effort behind every object and requires the standard to be expressed in a way that survives translation between very different data models.

Persuading manufacturers to participate

A library of manufacturer objects only works if manufacturers author to the standard. That is an adoption problem, not a software problem, and it depended on the library reaching enough designers to make participation commercially worthwhile.

Before national object libraries existed, design teams built BIM content one of three ways: authoring every object in-house, downloading whatever a manufacturer happened to publish on its own website, or buying from commercial content libraries of varying quality.

All three had problems. In-house authoring is slow and duplicates effort across every practice in the country. Manufacturer-published content was wildly inconsistent, with no shared rules for naming, classification, level of geometric detail or embedded data, and objects frequently arrived either as data-free shapes or as over-modelled families that bloated project models. Commercial libraries solved consistency at the cost of a subscription and rarely linked to specification.

The common failure across all three was that the model and the written specification stayed separate documents, maintained by hand and prone to drifting apart.

NBS has not published download or user figures that can be independently verified here, so no usage statistics are claimed. The library's significance is structural, and it can be described accurately without numbers.

A national reference standard

The most durable outcome is the NBS BIM Object Standard itself. By defining what an object must contain and how it must be structured, NBS gave the UK industry a shared reference that outlived the library as a product. Manufacturers gained a specification to author against; designers gained a basis for rejecting content that did not meet it.

Duplicated effort removed across the industry

Before the library, every practice authored or curated its own content, which meant thousands of firms independently modelling the same door, window and wall types. Publishing a free, standards-compliant national set removes that duplication at industry scale, which is a far larger saving than any single project could demonstrate.

Model and specification linked

Because objects were structured to NBS's data schema, placing an object could drive the written specification. Keeping the model and the specification consistent has always been a manual, error-prone task, and connecting them at the object level attacks the problem at its source rather than through downstream checking.

Support for the UK BIM mandate

The library arrived alongside the UK government's push toward BIM Level 2 on public projects. Free, standards-compliant content lowered the practical cost of compliance, particularly for smaller practices without the resources to build content libraries of their own.

A model other markets followed

National and standards-based object libraries have since appeared in other markets, including NBS's own Australian operation. The National BIM Library demonstrated that the useful unit of national BIM infrastructure is a content standard, not simply a file repository.

Programme details

Library: NBS National BIM Library. Operator: NBS, National Building Specification, owned by RIBA Enterprises Ltd, part of the Royal Institute of British Architects. Location: United Kingdom. Object authoring: BIM Academy, now trading as Okana, a joint venture between Northumbria University and Ryder Architecture. Content: generic and manufacturer BIM objects spanning fabric systems and mechanical and electrical components. Standard: NBS BIM Object Standard. Delivery: free plug-in for Autodesk, Bentley, Tekla and ArchiCAD platforms. Current status: content migrated to NBS Source; specification delivered through NBS Chorus.

A note on this entry

This case study documents a content library and an authoring standard rather than a constructed project. No company is currently linked to this record on aec+tech, although BIM Academy and NBS are both named in the source material.