BIM digital mock-up: definition, standards and software for better construction

The BIM digital mock-up, also known as the digital mock-up, or BIM mock-up depending on the school of thought, enables all those involved in a construction project to access the same computer file that models all the data for a building. The aim is to encourage collaborative working between all those involved in a project on the same file, in order to preserve data, optimise costs and, above all, improve construction by considering all the phases in the life of a building, from its design to its management. This is the BIM process. Digital mock-up standards such as the IFC file standard enable interoperability between digital mock-up software, so that data can be preserved and returned to each participant.

Are you confusing BIM with digital mock-up? What does the term BIM mean? What are the advantages of BIM and digital mock-up for each building-related trade ? Which BIM software should I choose? What are the criteria to be met? We can help you prepare for the challenges of Building Information Modeling in your speciality.

See all software Building Information Modeling (BIM)

Contents of our guide to digital mock-ups :

What is BIM?

• Definition of BIM
• Objective: better management of all phases in the life of a building
• 6 advantages for building composition and operation

What is a BIM digital mock-up?

• Definition of a BIM digital model
• A virtual 3D modelling principle enriched with data

Digital mock-up standards

• The IFC standard file format
• Standard XP P07-150, known as the PPBIM standard
• 6 BIM models to enhance your digital mock-up

The benefits of BIM for every construction-related profession

• For design offices, architects and engineers
• For construction and civil engineering companies
• For building contractors and subcontractors
• For civil and structural engineers
• For component manufacturers and suppliers
• For surveyors
• For building owners and developers
• For owners and asset managers
• For customers

Which BIM software should you choose?

• How do you choose your BIM software? 7 criteria for qualifying your needs
• Comparative table of the 3 most widely used 3D modelling software packages

Professional awards and certifications

• A trophy for Archicad
• A BIM d'Or for Revit
• 3 nominations for Allplan

What is BIM?

Definition of BIM

BIM ( Building Information Modeling) is a work process that consists of :

• the modelling of all the data relating to a building into a single digital file, the BIM digital model,
• a collaborative working approach between all the players involved in the construction process,
• smooth project management and data production at every stage: design, construction/implementation, operation and even demolition,
• the use of BIM software to work on the same digital model.

Today, BIM is essential in a context where the various players in the construction industry work in isolation, in silos, using different files and producing different data, resulting in errors, wasted time, poor workmanship and budget overruns.

With regard to the three initials of BIM, the "B" for Building stands for Build, the "I" for Information.

The "M" stands for the 3 essential concepts that will enable the construction industry to work together more effectively:

1. M" for Model means "maquette" in French. It expresses the need to bring together all the data and information about a building within the same digital model, in a structured way. This is known as the Building Information Model.


2. "M" stands for Modeling. It expresses the collaborative work process, Building Information Modeling, which enables the expertise of the various parties involved to be pooled using the same data, based on interoperability between BIM software.


3. "M" stands for Management in French. It expresses the project management associated with the life cycle of a construction: it involves organising and checking that the work process runs smoothly and that the data in the digital mock-up is shared. Building Information Management therefore refers to good construction project management.

Objective: better manage all the phases in the life of a building

Before joining the BIM process, the parties involved worked in sequential engineering: one person's work started when the other's was finished.

If a change occurs during a stage in the life of the construction, this can result in a lot of back and forth updating of information about the construction, multiplying the risks at all levels and leading to additional costs.

The aim of BIM is to operate as a form of simultaneous engineering: all the players are involved right from the start of the project, so that they have a better understanding of the ins and outs.

A BIM approach consists of promoting understanding and communication between the players by making all the information available to them: this access is provided by the digital mock-up.

The model clearly sets out all the life phases and technical components of a structure, so that the specialists can work together intelligently to ensure that the project runs smoothly, taking into account the previous or future requirements of the other experts. They can easily exchange and update information within a single file.

Each construction expert therefore knows all the information, the elements to be designed, produced, built, managed or operated, and the respective technical constraints, so that they can integrate them into their work. They can work alongside their colleagues without hindering the smooth running of the project - quite the opposite, in fact. The time factor changes dimension.

In this way, each player works with the knowledge of the pre-established model at each phase of the project:

• feasibility
• design
• construction
• operation/management,
• renovation, rehabilitation,
• demolition.

A project manager needs to be appointed to coordinate everything from the outset and ensure that everything runs smoothly. This specialist is often a BIM manager.

6 advantages for building composition and operation

To sum up, the main benefits of BIM can be seen at every level: designing, constructing, renovating, managing and operating buildings in the best possible way.

Benefit no. 1: run simulations before making decisions

BIM technology is a great decision-making aid: by carrying out tests and simulations using visual representations, you can check the relevance of the data, assess the budget required, eliminate duplication and errors, and reduce deadlines.

Advantage no. 2: keep control of the project

For each stage, you can accurately plan the degree of complexity, the requirements and anticipate any difficulties. There are no more unpleasant surprises along the way...

Advantage 3: Reduce costs and shorten lead times

Information is centralised and accessible to all the players involved at the same time, throughout the building's life cycle. Understanding, collaboration and organisation are optimised, problems are detected and avoided, and costs and timescales are reduced.

Benefit no. 4: save documents and energy

Writing information digitally means fewer documents, no more multiple versions. The use of a digital mock-up where data is centralised gives simplified access to the players involved, eliminating the need to repeat time-consuming tasks.

Benefit no. 5: greater profitability

Saving time, eliminating errors, collaborating: you cut costs and shorten the delivery schedule.

Benefit no. 6: a qualifying European professional standard

The law on public procurement in France, which came into force in 2017, gives contracting authorities the option of imposing the use of digital mock-ups. It is up to the client to determine the objective, methodology and level of the mock-up.

Already initiated by European Directive 2014/24/EU of 26 February 2014, this approach reflects the desire to plunge construction professionals into the era of digital transition, and ultimately to make it a differentiating professional requirement.

What is a BIM digital model?

Definition of a BIM digital model

A BIM digital mock-up, also known as a digital model, is a computer file containing virtual objects relating to a building:

• It is a virtual representation of the building,
• It is an interactive 3D model of the physical and functional characteristics of a structure,
• The model provides the various parties involved with information on all the technical specifications, such as spatial relationships,
• The file details all the phases in the life of the building and all the players involved,
• also known as an avatar, it simulates the reactions of the 3D objects and technical equipment that are part of the construction,
• It enables the reactions of each mechanism to be analysed and tested in advance, such as stability, energy performance and environmental impact,
• Each trade specialist interacts with the file to update it and exchange information with the other experts.

Controlling, centralising and sharing information are the key elements of a BIM model: a single database stores all the information! Each expert adds to this database as the building progresses: updating technical information, new documentation, new equipment, etc.

A virtual 3D modelling principle enriched with data

Digital technologies have evolved: digital modelling goes beyond the notion of a virtual mock-up, or 3D representation in the strict geometric sense of the term, to create an intelligent, updatable and interactive working tool that can also be used over time.

When the English-speaking world talks about digital mockup, we mean digital model, which includes all the concepts of objects:

• details of each object, such as walls, beams, doors, staircases, mechanisms, lifts, slabs, windows, etc.
• architectural and technical characteristics
• possible interactions between objects, common features in the materials used, wall junctions, the effect of wind, etc.
• simulations, energy measurements, solidity, etc.
• the organisation and classification of information relating to these objects (example of arrangement: site, building, floor, space),
• the evolution of the stages of construction, and even the life of a construction by elements.

The digital mock-up is integrated into the BIM collaborative work process and evolves over time: each time work is carried out or changes are made to the construction, the file is updated to enrich the database and reflect reality. This makes it possible to monitor the progress of a project and prevent potential risks in the event of an incident or delay.

Digital mock-up standards

The IFC standard file format

This is clearly a digital revolution for the building industry: the IFC format(Industry Foundation Classes) is a standardised file format that can be opened in the various dedicated building software packages.

It therefore facilitates communication between the various specialists and their tools. Players can exchange and share information between software packages in a collaborative manner: the database structure is therefore one of the BIM standards.

An IFC works on a semantic model based on the notion of object, with one object representing each element that is part of the building: floor, wall, space, window, ceiling, columns, etc.

Modelling objects is what makes digital mock-ups so interesting:

• each object contains information such as its characteristics
• interactions with other objects are indicated,
• each specialist can approach the object from their own point of view or that of others (architectural, window nomenclature, structure, thermal view, axonometry, etc.),
• modelling means that information can be shared at every stage in the life of the project,
• no need to modify several files to update the documentation.

The latest update of the IFC format is version IFC4, which has been awarded the ISO 16739 standard. This version of the IFC format includes a number of improvements:

• 113 more object classes (766 classes in total), including the boiler class,
• elimination of model interpretation problems,
• energy assessment and carbon footprint,
• integration of spatial zones,
• estimation of environmental impacts,
• the ability to model more geometric shapes, particularly for architects,
• complex shapes are easier to represent
• more comprehensive documentation.

Note: some software such as Revit or Autocad can read and write in IFC4 format. It is therefore important to use this type of software to benefit from the latest improvements and BIM standards.

Standard XP P07-150, known as the PPBIM standard

At the instigation of AIMCC (Association des industriels des produits de construction) and Mediaconstuct, the PPBIM standardisation committee of AFNOR (Association Française de Normalisation) published the XP P07-150 e 2014 standard.

The objectives of this standard are, in stages:

• to compile a common dictionary in order to establish terms that harmonise the naming of products, tools, practices and methods in the building sector,
• to use the same terms for objects, their properties and their classification, to make better use of them in the digital mock-up,
• Set up standardised object libraries based on an established reference system,
• facilitate the exchange of data between construction professionals.

The XP P07-150 standard, known as the PPBIM standard, has been submitted to the European Committee for Standardisation and has become the focus for the development of data models produced within BuildingSMART international.

6 BIM models to enhance your digital model:

Model 1: 2D BIM for project design

At this level, we're still talking about 2D geometry requirements, with the option of translating them into digital 2D plans.

Model 2: 3D BIM, modelling for collaborative working

The digital mock-up models the structure in 3D: as already mentioned, the IFC file facilitates access to the same information, and collaborative working.

Model no. 3: BIM 4D, plus time management

This 3D BIM model also includes a timetable for planning work and viewing progress in real time.

Model no. 4: 5D BIM to combine costs

This 4D BIM model also includes budget and expenditure data: calculations can be automated to assess costs and cash flow forecasts.

Model no. 5: 6D BIM to incorporate the sustainable development dimension

This 5D BIM model also integrates the sustainable development dimension of a building, for example energy performance estimates.

Model 6: 7D BIM for monitoring and maintenance

This model is designed to help property managers, suppliers and subcontractors during all phases of post-construction maintenance: BIM 7D provides all the information on the machines present and specific data on procedures such as manuals and standards, in order to monitor the condition of the entire building and ensure its good health.

The benefits of digital mock-up for every construction trade

For design offices, architects and engineers:

• visualise a construction project at every stage,
• view the building from every angle,
• design by analysing the model from every angle,
• check and simulate the life of objects,
• correct defects and avoid errors,
• generate 2D plans on the fly,
• comply with standards,
• have permanent access to all the information (budget, timing, etc.),
• anticipate accordingly, in particular to meet energy performance requirements,
• apply a sustainable development approach.

For construction and civil engineering companies:

• take delivery of the digital mock-up or produce it themselves (e.g. by combining different digital mock-ups),
• Examine the site prior to construction,
• identify risk areas upstream so that appropriate safety measures can be put in place,
• evaluate the design to identify possible errors,
• use the database to prepare the site,
• check progress and control costs in real time,
• regulate the supply chain,
• reduce delivery times by using off-site prefabrication.

For building contractors and subcontractors:

• Identify any errors or omissions,
• gain an overall view of the project and the interactions between the various parties involved,
• analyse interventions and detect potential negative interactions between trades,
• modify the digital mock-up rather than reacting once the project has progressed to a given stage,
• see the effects of corrections on the BIM model as a whole,
• synchronise design and construction,
• know what materials and resources to plan for at each stage of construction,
• streamline the flow of equipment and materials deliveries,
• optimise the timing of work and orders placed with subcontractors.

For civil and structural engineers:

• receive a usable model, without redrawing plans,
• know the structural elements thanks to the 3D model,
• modify the structural model, which the architect will then transfer to the architectural model, directly in the digital mock-up,
• draw up reinforcement plans based on a pre-established and functional BIM model for designers,
• anticipate fabrication and shaping by launching them remotely,
• Reduce the risk of errors,
• save considerable time for the entire engineering office.

For component manufacturers and suppliers:

• Understand the needs and expectations of designers, manufacturers and maintenance personnel,
• provide objects that can be used in a BIM digital model,
• Offer quality objects containing relevant and structured information, making them easier to manipulate in the model,
• offer usable objects for all stages: design, construction and maintenance.

For the surveyor:

• Create an initial digital model enriched with 3D data upstream of the project,
• Drive quality upwards by evangelising the expectations of the construction sector, such as sustainable development,
• Facilitate a change in mentality in the interests of all concerned (collaborative working, interoperability and benefits for everyone involved),
• guarantee the restitution and transition of information for better regional management,
• promote the correct use of a workable model based on key criteria,
• be able to intervene at every stage and include its Carrez law measurement or division of volumes in the model,
• be able to intervene to ensure that the building constructed meets the established specifications.

For project owners and developers:

• extract information to validate or not the feasibility in terms of budget and time,
• improve the building by correcting functional or environmental anomalies,
• assess in real time the repercussions of an incident, such as changes to the design,
• encourage the involvement of all the experts through better understanding (the quality of a building is everyone's business).

For owners and asset managers:

• benefit from all the information they need at every stage in the life of a building,
• anticipate installation options or obligations,
• manage their property more effectively,
• carry out effective maintenance work.

For customers:

• Reassure themselves that their project is running smoothly at every stage,
• benefit from lower costs,
• reduce project delivery times,
• consume less energy,
• reduce waste and carbon emissions,
• enjoy optimum safety during use,
• improve building performance.

Which BIM software should you choose?

How do you choose your BIM software? There are 7 criteria to help you assess your needs:

Criterion no. 1: the software's good reputation

If the name of a software package is often mentioned by specialists in complementary fields, that's a good sign: it's being used successfully by different players.

It's a good idea to rely on software that promotes best practice through regular updates, like Revit for example, which benefits from significant new features and improvements.

Criterion no. 2: interoperability with other software

Should your BIM software be able to work with your third-party software such as Microsoft Excel, Word Crystal Reports for reporting, project management software or workflow?

The whole point of BIM and the digital mock-up is the exchange of data that can be read by other players in the construction industry: your software must be able to read the IFC format in particular to be compatible with other software, and handle objects using the same nomenclature.

In addition to the IFC format, you can also ensure that you can read and write certain other formats: IFCXML, IFC 4, PDF (Acrobat Reader) JPG, TIFF, BMP, PNG, RVT (Revit software), DXF/DWG and 3D DWG, etc.

Criterion no. 3: real-time collaborative working

Criterion no. 4: Functionality

Depending on your business and working methods, you should also consider the following points:

• for architectural design, you need to be able to take advantage of 3D design visualisation and a free-form model design tool,
• on the engineering and MEP manufacturing side, you need software that integrates manufacturing documentation,
• from a structural point of view, functionality capable of managing reinforcement constraints or gravity analysis, for example,
• for the construction part, modelling and construction coordination functionalities are essential.

We refer you to the BIM model chosen beforehand.

Criterion no. 5: the BIM object library

In 3D object catalogues, professionals download ready-to-use objects to insert into their digital mock-up model, rather than creating them.

To make the most of the time saved, however, you need to check that the format of these objects is compatible with your software.

These libraries of 3D objects dedicated to BIM generally offer the IFC, 3DS and RVT formats (the Revit software format, which also reads IFCs):

• Autocad and Revit take the cake for variety, with no fewer than 16 sites and almost 70,000 objects,
• Archicad has 10 sites and 1021 objects,
• Sketchup has 9 sources,
• Allplan has 4 suppliers.

Criterion no. 6: Ergonomics and ease of use

Although Revit Architecture, one of the most advanced BIM software packages, requires more training time than Allplan, ArchiCAD or Sketchup Pro, it is worth considering what it offers in comparison over the long term: we refer you to the points already mentioned.

Criterion no. 7: Customer support, guides, resources and tutorials

You always learn better when you have support to help you get to grips with the software. On this point, we note, for example, that there are more videos on Sketchup pro and Revit. Is this a factor in your reputation?

It's up to you to find out...

Note: prices change from year to year as improvements, compatibility and new features are added. We advise you to compare offers.

Comparison table of the 3 most popular 3D modelling software packages

Poll: Allplan, Revit or Archicad?
The Hexabim professional community responds:

See all software Building Information Modeling (BIM)

Professional awards and certifications

We think it is useful to provide you with this information, which may help you in your choice of software. The efforts of publishers to provide the best BIM software are rewarded:

A trophy for Archicad

ArchiCAD has won a trophy in the design tools category at the 2016 digital transition awards organised by the PTNB (digital transition plan for the building industry).

A BIM d'Or for Revit

The BIM for FM experimentation project, which uses Revit in particular, was awarded a BIM d'OR in 2016, under the watchful eye of professionals such as Bertrand Delcambre, President of the PTNB, and the 300 players representing architecture, construction, engineering, and private and public project management. Note: Revit has also been nominated several times in different categories at the Digital Transition Awards.

3 nominations for Allplan

Allplan has been nominated several times for the Digital Transition Awards, but has failed to win in the following categories:

• design tool,
• structure and shell,
• business tools for project management and operations.