UK BIM Level 2 Model Progression Specification – A Review

Part one:

With the April 4th, 2016 UK BIM (Building Information Modeling) Level 2 rollout date passing, many in the construction industry will be wondering how does the UK Model Progression Specification (MPS) stack-up. Where is it innovative, where does the approach require improvement and how does it differ from other MPS approaches, such as the AIA G202TM which includes LOD (Level Of Development)?

What is a Model Progression Specification (MPS)

The below is an in-progress draft definition. All comments and feedback are welcome:

An MPS is a set of frameworks around the Goals, Planning, and Management for progressing Information Models and their constituent parts. The MPS should enable the basis for reliable Structured Project Information; collaboration, coordination, and data use between participants.
The MPS may identify the progression (possibly down to a constituent level) of Information Models, including:

The project implementation aspect of the MPS frameworks is often within the project BIM Execution Plans. However, other frameworks such as Contractual Agreements, industry Standards, Specifications, Employer Information Requirements, and any project development plans will greatly influence the MPS.
MPS is intended to be a non-proprietary collective term for the above frameworks.  The MPS has also been referred to as Model Development Specifications, and Level of Development frameworks.
There are currently no MPS Frameworks which include all of the above aspects. MPSs will evolve over time to be an integral aspect of the Projects planning, delivery, and operations.

Thank you:   I would like to thank Marzia Bolpagni (twitter: @m_bolpagni), for her time and feedback in providing peer review on the above MPS wording. This draft MPS definition is the basis of the scope of the below article.

BIM Task Group right to reply:
I invited the BIM Task Group 2 the right to reply, two weeks before publishing. I would like to thank them for reviewing and providing the following comment:

"Looks good nothing to add other than happy to see people (you) taking the initiative and driving things forward."

Article Breakdown:  Due to the length of this research work, I have broken it down into two parts. Part 2, which describes how the UK BIM Level 2 MPS works. Part 1 is below.

UK Level 2 MPS Basic structure:

Much of the scope of the UK Level 2 BIM comes from PAS 1192-2:2013. However, the UK Level 2 BIM Model Progression Specification is built on four main frameworks, and supporting documents and tools:

Above: The four framework schemas on which the UK BIM Level 2 MPS is formed.

Note:  Please do not confuse the above with “The 8 Pillars of BIM Level 2”. The UK BIM Level 2 is obviously more than just an MPS.

For a detailed understanding of the UK Level 2 BIM MPS please refer to the second section of this article, which goes into detail around the frameworks of the UK Level 2 – Model Progression Specification. I also highly suggest reading the recently published: Design Buildings Wiki, on “Step-by-step guide to using BIM on projects”. It is a MUST read before reading PAS1192-2:2013, and will greatly assist your comprehension of PAS 1192-2:2013.

UK BIM Level 2 MPS findings:

The UK Model Progression Specification: Where it works well:


Integrated approach:   Seamlessly integrates into the project development and delivery. Other than the Level of Definition sections, it is very difficult to extract the MPS portion from the overall solution.

Lifecycle Integration:   Starts with the Client before Briefing Stage (Stage 0) and ends with a Client during operations (Stage 7); thus, in theory achieving the mythical BIM Asset Life Cycle we are told to strive for.

Familiar Approach:   Aims to neatly fit into traditional design and construction stages, creating a familiar delivery approach for the project team members. Thus, the frameworks are easier to understand and achieve industry uptake.

Upfront EIR:   Being able to provide the project team with a clear and concise brief of the Clients/Employers Information Requirements (EIR), is key to ensuring project expectations can be achieved in an efficient and timely manner. The level of information requirements provided in the EIR by the client and subsequent employers in a format like this is a world first. The concept of an EIR will be taken up across the globe, but will mean the Client will need to get appropriate BIM Consultants engaged upfront.

Legal:   Provides the CIC BIM protocol as a freely availably contractual addendum to the industry, creating a familiar BIM contract addendum and assisting parties to reduce their liabilities.

Warranties:   The CIC BIM Protocol, Clause 5.1 makes clear that, without prejudice to its obligations under the Agreement, the Project Team Member gives no warranty as to the integrity of electronic data. This appears appropriate.
I have been hearing situations where Employers look for warranties for Information Models. I don’t believe the Employers making these requests understand the immense ramifications of such a request.
Put simply, an Employer can only think about warranting data, if the data provided by any input is also warranted. Thus, the Employer would need to warrant the information they provide, in order to receive a warranty on the supplied goods. To add to this, the additional time in quality control and insurance costs would exponentially blowout.

Model Element Table:   (AIA G202TM term) Has a compact approach (1 page) and is called the Model Production and Delivery Table (MPDT). It means the team is not spending unnecessary time filling out detailed model element tables, which are unlikely to be truly used. Including the MPDT into the BIM Protocol makes it contractually binding.

Clear BIM Roles:   The requirement for the establishment of BIM Roles up front in the project, gives the project the best chance Information Modelling outcomes will succeed. The UK Level 2 BIM Projects have predefined roles and responsibilities as per PAS 1192-2:2013 Clause 7.5. These include Information Manager, Project delivery management, Lead Designer, Task Team Manager, Task Information Manager, Interface Manager & Information originator.

BS 1192:2007+A2:2016

DMS Integration:   Including BS1192:2007+A2:2016, facilitates a clear intent of how the UK MPS integrates into a Document Management System (DMS), in this case, the Common Data Environment (CDE). It includes how data is shared, file status and suitability (appropriate use), and a version control system. It identifies approval workflows and file naming conventions and many Quality Control mechanisms.

Site Coordinate Establishment:   As simple as it should be, clearly stating the coordinates of the site and building as early as possible is extremely important. In Annex A.3, by engaging a Map (Site) Grid with identified coordinates enables a clearer process of sharing graphical digital data between parties using Meters to World geospatial coordinates, compared to those using millimeters and working to a local site origin.

Model Single point of data:   Clause 4.2.3 identifies model geometry in the shared area will not be duplicated (i.e. information occurs only once). Thus, content included in the geometry/information must be only items which are the responsibility of the originator. This identifies clear workflows on how parties should be using and testing information.

Litigation:   The Guide to BS1192 – on page 23 also clearly identifies the legal status of the relevant model Suitability’s, however, is information does require updating.

RIBA – Plan of Works: & BIM Toolkit:

The Right Information at the Right Time:   You will hear this a lot when it comes to people writing about the UK approach. The concept is data/geometry is produced in a just-in-time or Lean timeframe. This reduces waste during production. We all want to work this way, but it will mean the individuals managing the project will have to be very good planners, ensuring the Plan of Works are logically and thoroughly documented.

Task & Modelling Allocation:   Engages the project responsibility matrix (within RIBA Plan of works) for the entire project team, and not just the model authors. This ensures the most senior leads are making the correct decisions about responsibility, planning and production.

Programme Planning Integration:   Leverages off the RIBA Plan of Works enabling the team to better plan and allow for sub-milestones and order of works.

Standardized Stage Deliverables:   Combining all the tools provides a clearer understanding of what a Stage 2, Stage 3 and Stage 4 outcome should look like, assisting it standardizing it across the UK industry. This should lead to consistent workflows and expectations.

BIM Toolkit Definitions Library:   This web-based resource does a similar job to the BIMForum LOD Specification, but in addition it scope includes infrastructure facility componentry and 2D Documentation generated from the Information Model. It has over 7000 definitions.

Practical Timelines:   How often do fast track projects become a fast track to poor working environments and outcomes. The Plan of Works as a tool assists delivery teams and clients in not setting unrealistic time frame targets by breaking down the program, including all relevant milestones and approvals. It won’t completely remove unrealistic deadlines, but it will enable transparency, where clients are unwilling to allow for due process.

Includes Documentation:   Does not only include graphical and non-graphical data (including COBie if requested in the EIR), but it also includes documentation deliverables generated from the model; such as PDF drawings, Schedules, and Specifications.

Above: A diagram of the Information Model. Image from Mervyn Richards OBE and Barie Hasib. YouTube video: BIM REC. A Year With PAS1192 and What Is BIM Level II.

Model Functions:   Acknowledges the differences between Design Intent Models, Virtual Construction Models, and an Asset Information Model (AIM). It acknowledges Design Intent models will contain non-proprietary products unless the designers specifically say otherwise.

As-Builts:   Has the most comprehensively defined approach to generating As-constructed models compared to other Model Progression Specification’s, such as AIA LOD 500 within G202TM.

Classification:   The UK BIM Level 2 delivery approach engages Uniclass 2015. This is one of the most developed construction industry classification schemas and has been updated in the past few years to better cater for BIM use. The long-term benefits of a clear data structure and common language are immense, it can be engaged across: library structures, room data sheets, schedules, specifications, costing, programming, tendering, construction logistics, building codes, product/part selection, and replacement.

The UK Model Progression Specification – Where improvements are required:

EIR (Employer Information Requirements) and the BIM Protocol:

Non-standard Structure:   The sample BIM Task Group EIR has a section numbering format, however, none of the BIM Level 2 frameworks specifies this numbering structure must be followed. In the sample EIR’s published to date (see part two of the article), we see most parties producing their own order of contents, generating inefficiencies in the return Pre-Contract BIM Execution Plan. Ideally, the EIR would have a set section numbering and BEP would match this, section by section.

At the end of the day, it’s a patch:   The plan for what information will be delivered has to be the cornerstone of a BIM Level 2 Project. This plan is influence from the Employer’s: Scope of Services, Responsibility Matrix, EIR, Model Production and Delivery Table (MPDT) and what is outlined in PAS 1192-2:2013 Clause 9.8 (which includes the Level of Definition outcomes from Stage 1 to 7).

On the supplier’s side, the proposed delivery of information is in the Master Information Delivery Plan (MIDP). It is a compilation of the Construction Programme, Task Team Information Delivery Plans (TIDP) and Responsibility Matrix (RM), and in turn is a subset of the BIM Execution Plan (BEP) which is submitted firstly pre-contract. 

Above: Part extract from PAS 1192-2:2013 Figure 4

Out of all these documents, there is a lot of duplication. Thus, there is a good chance they may contradict one another. In regard to what should be in the contract, we are advised in PAS 1192-2:2013:

5.1.5 The employer, or the employer’s representative, shall be responsible for ensuring that [Employer’s] information requirements are included in project contracts in such a way as to avoid duplication of responsibilities.

Adding to this, the procurement approach will have an influence, potentially generate duplication of responsibilities or even create gaps in the final scope. During the tender negotiation, how are updates to the EIR captured in the contract? What exactly gets included in the contract. What occurs in a dispute if any of the Employer documents contradict each other? 

The big problem I see, the BIM Protocol is a “patch” document, attached to existing contracts. How well this patch will work will only be known when tested in court. Until an Information delivery approach is integrated into building contracts, we are always going to have potential problems.

MPDT in Question:   With the above mentioned, it is difficult to see how the client end Model Production and Delivery Table (MPDT) contains information that is not already identified. The bottom line question: is this the leanest way to convey the Employers Information Requirements and Model Production plan? PAS 1192-2 does not even define what an MPDT is. It only states: 5.3  a) information management:

  1. )    levels of detail – e.g. requirements for information submissions at defined project stages. This is needed to populate the Model Production and Delivery Table required under the Protocol;

The above even incorrectly uses the term “Levels of Detail” when it should refer to “Level of Definition”.

Protocol shortcoming:   According to the BIM Protocol: Models which are not listed in the MPDT do not benefit from the provisions of the Protocol.” yet, the sample MPDT does not mention models. It only identifies supplier / authors, the Level of Detail and stage delivery. 

Above:  Extract from the sample Model Production and Delivery Table (MPDT) in the CIC BIM Protocol.

Clarity on Contract Documents:   BIM Level 2 is fundamentally the Client purchasing structured data about their recently constructed asset. At no point in the CIC BIM Protocol or PAS 1192-2 are the Information delivery related documents specifically identified which will form part of the contract? E.g. between the outcomes requested in the tender EIR, MPDT, the return MIDP and BEP. Etc. This area requires clarification.

Tender Evaluation:   It is difficult to understand how much weight will be given to the Pre-contract BEP during the return tender evaluations. If the client awards on a cost-centric outcome, it is difficult to believe, in the short term anyway, the winning bidder being BIM proficient. At handover, if the information provided is substandard, it’s unclear what course of action the client can take. We will just have to wait and see.

Different Terminology:   Some of the BIM Task Group sample EIR’s terminologies are different again compared to the CIC BIM Protocol and PAS 1192-2  (e.g. EIR referrers to Information Requirements & data drops. PAS1129-2 refers to Employer Information Requirements and Information Exchanges).

AIM Suitability and Use:   With the current Level 2 BIM frameworks and EIR’s samples, I am yet to see anything where a client can clearly and easily state how they intend to use the Asset Information Model.   An example of such uses can be found at the BIM excellence website – Model uses list. Without this, the client is taking on all the risk, as a supplier cannot deliver a product fit for purpose when the purpose is unknown.

Limited Collaboration:   The CIC BIM Protocol and PAS 1192-2 were compiled by two separate parties, and it looks like the collaboration between them was poor. The Definitions and terms used in the CIC BIM Protocol are very different to what is defined in PAS1192-2. Thus, unless the Client corrects this in the first use of the addendum, legal action outcomes are very unpredictable. Some examples:

  • BIM Pro. refers to a Model, while PAS1192-2 engages the term Information Model, which is defined very differently.
  • BIM Pro only refers to Level of Detail, when it should refer to Level of Definition.
  • BIM Pro’s definition of “Material” is very different to in the NEC3 & JCT Contract. – As the BIM Pro overwrites the other contracts, this potentially opens up other liabilities on the traditional deliverables.

Engaging a BIM Consultant:   It is difficult to imagine a client putting an EIR together without engaging a BIM consultant to assist in writing it. The client will need to cater for this appointment and allow extra time and budget in the pre-briefing stage (RIBA Stage 0). In the short term, I imagine many private sector clients wanting to follow a BIM Level 2 process, will miss this critical step, and thus not achieve BIM Level 2. They will need to engage an Information Manager also during Stage 0, and I can see all BIM consultants will be trying hard to get this role. I can sse the Architect will chase this role position also. As we begin BIM Level 2, there will be a lot of BIM Cowboys out there. Only time will tell to see who is the best to fill these roles.

Container Limitation:   A container within the process is currently limited to a file level within the CDE, despite the intention of a container to be able to go down to an elemental level. The consequence of the current approach is models may need to be split up if elements have different Suitability assignments. This is very labor intensive, means attributed data has to be transferred between models, and is unnecessary. Having the flexibility to allocate a suitability down to an elemental level opens up greater flexibility within workflows, especially during the construction stage, when elements can be still in design, others undergoing shop drawing approval’s, and some installed elements being recorded as, as-constructed, and this is all within the same trade.

Unclear Process:   The Process workflows for the Suitability (Table 5 – See part two of the article) are unclear. Users will need to read up on the Guide to BS 1192 which is now out of date. There is no advised workflow on S6 (PIM Authorization) and S7 (AIM Authorization) suitability levels. This will result in team members not complying with the intended workflow. I believe the Suitability section is the most important part of BS 1192, but it is also an area that requires further clarification on its use.

Naming Convention:   The Container naming convention is an archaic approach to managing Containers on a Document Management System (DMS). The standard is more suitable for a Windows based file system (this is acknowledged in PAS1192-2:2013 Clause – We are in the 21st Century and attributing Meta Data to files / objects is the preferred practice and enables far superior functionality. Yes, a simple standard approach to file naming is absolutely required, but the current BS 1192 naming regime (including; Project, Volume, Level & Classification) will cripple innovation and efficiencies. We now have second-rate DMS System’s, achieving BS 1192 compliance, when the advanced forward thinking DMS systems are not technically compliant.
With all the identifiers BS 1192 inserts into the container file naming, it misses is a building asset identifier and a project stage metadata attribute.

Information Model Segregated:   Suitability level “S4” (Release to Client - Stage Sign Approval), is only applicable to the Documentation (i.e. excludes and Graphical and non-graphical data). Why would the design team put time an effort into the Model (graphical and non-graphical data) if the client will not be scrutinizing and reviewing it?

Image above – cut down version of table 5, showing S4 Graphical and Non-graphical data, as excluded.

Content Not Added:   When PAS1192-2:2013 (Clause 9.2) came out, it contained a lot of additional detail on the Common Data Environment (CDE), expanding on the older BS 1192:2007 document. Much of this work was not added to BS 1192:2007+A2:2016 update, despite, BS 1192 being a much more appropriate location for it.
There are also sections in the Guide - (.e.g. Page 23 – Provides greater clarification on Suitability, including their legal status) which should have been included in the update to BS:1192:2007+A2:2016.

Document Errors:   For a document that has been revised twice in the past 9 months, it still contains terminology errors, which lead to confusion and incorrect implementation. (e.g. Table 5, see part two of article, uses the term heading “Status” when it should use the heading “Suitability”).

Attributed Data not supported:   BS1192 was first created to be used with projects engaging Computer Aided Design (CAD) workflows. It now has been applied to BIM projects. Thus, the concept of attributing data to containers / elements is not considered. This misses a huge opportunity. It’s a bit like building a motorway and saying the speed limit is 60km/40 miles per hour. 

Cloud Based building data management tools are the way the industry will need to go. Examples are dRofus, and CodeBook Cloud. These types of tools enable the entire project team to contribute to the Information Model and have a complete audit trail, including previous data. They are the closest tools we have to a Level 3 BIM philosophy (understanding that Level 3 BIM has not been actually defined yet). They, however, are not BS 1192:2007+A2:2016 compliant as they sit outside the CDE. Ironically, these tools are essential to meet the PAS 1192-2:20013 Clause 9.5.4 “At build and commission stage any generic object shall be replaced with the object procured from the manufacturer. Any essential information to be retained shall be reattached or relinked to the replacement object.”

Sharing around the CDE:   BS 1192:2007 does not acknowledge the need to sharing information between parties, which does not meet the CDE requirements.  This may include preliminary design studies and the use of one party graphically placing an element spatially, to enable the responsible authoring party to put it in the correct location. One example of this would be an Architect, putting a Light fitting in their model showing the updated location of it, followed by the Electrical designer relocating their Light fitting to the new location. So when these parties need to exchange the relevant information, they need to go around the CDE. There are many, many other examples. This workflow needs to be acknowledged with appropriate advice/directions provided.

Security in the CDE:   All information on the CDE is available to everyone. At no point in BS 1192 does it acknowledge this is not always appropriate, and when it isn’t; how should the CDE be setup.

Hyperlinks not supported:   BS 1192 at no point mentions the use of document hyperlinks. For an industry wanting to have a lean environment of one point of truth, product data information really should be referenced from the Product Manufactures website.

Native File formats unlikely to comply:   Technically all data that is released into the shared CDE are to:
  • Only contain approved content:
  • Only contain content the author is responsible for:

However, Native files will contain unapproved content such as Jigs/Templates or items used with the authors workflows. On release, all of these unapproved items must be stripped out. How easy and time consuming this will depend on the authoring application. This workflow also requires the Lead Designer to review the Information Model before release.  It would be interesting to know, how much this actually happens.

Level of Definition (within Clause 9.8 - PAS1192-2:2013)

Sub-milestones during Construction:   Assigning one definition to the entire construction stage does not acknowledge the sub-milestones involved during construction. These may include:

  • Set-out / Layout, In situ Construction with nonspecialist trades,
  • Shop drawing / Fabrication and approvals,
  • Temporary and builder’s works,
  • Product approvals and submittals,
  • Erection and installation of products/fabricated parts,
  • Commissioning,
  • As-constructed verification and model updating,
  • Defecting / Snagging / Punch lists.

To compare this to the AIA LOD approach, UK’s LOD5 combines AIA’s parts of LOD 300, LOD 350, L0D 400 & LOD 500 into one. This makes the Level of Definition – Stage 5, unusable for a contractor, and without the contractor breaking it into LOD5.1, 5.2 5.3 etc., for different tasks and sign-offs, I don’t know how it can be engaged.

Early Contractor Involvement:   From PAS 1192-2 Figure 20 (Levels of model definition for building and infrastructure projects), unless a contractor is engaged from design Stage 2 to 4, the rest of the team are unlikely to be able to deliver the Construction Requirement (Fig 20) outcomes for these design stages.

Content Comprehension:   PAS 1192-2 Figure 20, is extremely difficult to understand, due to its format and presentation. It looks like the layout was chosen only to enable greater comparison. By providing the information in a traditional linear approach (see example in the part two of this article) it is far easier to comprehend. Each of the sub-items in the table should be numbered to enable better cross referencing.

Design Intent to Construction Model:   As per Clause, much of the design intent model will be remodeled and replaced with manufacture’s products or fabrication components at Stage 5 by the specialist sub-contractors, yet all attributed data is to be retained. The only way I am aware of doing this is having the non-graphical database separate to the graphical geometry and linking the database to the new/old element by the same identifier code. PAS 1192-2, however, gives no recommended solution for this potential showstopper.

Elements, which don’t require specialist sub-contractors input, will remain owned by the design authors.  Examples of these may include: in situ concrete and internal linings, trims, and furnishings. The project team will need to understand what extent will be taken up by specialist sub-contractors, how the design intent components will be used on Site, and how the contractor will communicate as-constructed deviations back to the designer if they are the responsible party. PAS 1192-2, unfortunately, does not shed any clarity on who bears the responsibility for these as-constructed components, which is an obvious shortcoming.

Over Detailed AIM:   There is minimum process acknowledgement of downgrading the level of graphical detail of a construction model at hand over to the client as an Asset Information Model (AIM). It is highly likely if a client was to utilize the Information Model at LOD5 in a BIM for FM approach, it would be too detailed and geometry heavy. Pyrmont Bridge, Darling Harbour Sydney, is an example where an over detailed model had to be stripped back, in order for it to work on mobile devices.

Not at an Element Level:   As Level of Definition does not currently go down to the granularity level of elements, it is not possible to understand how the assemblies are developing during the design and construction stage.  There is also no indication that the Level of Definition suitability would be attached to the model elements. Whereas in the AIA Level of Development we are advised there is no such thing as a LOD 300 model, under PAS 1192-2 we definitely can have an LOD3 model.

Product Data Templates:   I originally had thought completed Product Data Templates (similar to SPie) were a requirement for all product suppliers bidding for a BIM Level 2 project. Apparently I was wrong. This is a massive step backwards in my opinion. Structured product data is a game changer for BIM, and would remove much of the incorrect data within Information Models related to products. It would be massively beneficial to the entire project team, and in fact, enable better competitive tendering, bringing the project costs down.

LOD5 is Broken:   During construction, Stage 5, elements are to be brought up to LOD5 (Level of Detail 5) progression (PAS 1192-2 clause 9.9.5) and replaced by the “object procured from the manufacturer”. This is the same for a Fan Coil Unit as it is for a Task Chair. These two objects spatial coordination requirements are poles apart.  There is no return on having the chair at an LOD5. It is likely to hinder the model. However, a Fan Coil Unit’s level of detail will need connections, hanging structures, and maintenance access zones to enable the required collaboration. LOD5 needs to be re-written to provide better value to the project team.

LOD Acronym Confusing:   The acronym LOD should never have been adopted for the UK BIM Level 2 frameworks. There are other systems in use in the UK and Globally which use near identical acronyms and numbering, e.g. CityGML. The Level of Definition should have been call “Model Definition Level” (MDL) and Level of Model Detail’s acronym engaged should be:(LoMD). This would have clearly separated out the UK Frameworks from other MPS’s and enable greater international uptake, which is a fundamental goal by the UK Government.

What’s worse is that none of the documents are consistent in their terminology: 

Below is the table of the count of the number of times the different terms used in the different documents:

EIR Template
PAS 1192-2
PAS 1192-5
RIBA Plan of Works
Level of Model Definition
Level of Definition
Level of Model Detail
Level of Detail
Level of Model Information
Level of Information Detail
The above shows how inconsistent the basic terminologies are.


Comprehension:   It is a very difficult document to fully comprehend. After studying and reading it several times, I struggle to say I really understand it. If a supplier has a Level 2 BIM project starting next week and thinks they can get their head around PAS 1192-2 over the weekend, they are in for a shock.

Contradictions:   There are several apparent contradictions within it, due to not explaining workflows and context clearly. E.g. According to Figure 6 (Information delivery – Procurement), Procurement occurs before Design Stage 1 (RIBA Stage 0). Whereas Figure 20 - Levels of model definition for building and infrastructure projects (Page 36) says procurement occurs in Stage 1 (Brief).

Out of Date:   It itself is out of date. In its own words (This PAS will be reviewed at intervals not exceeding two years, and any amendments arising from the review will be published as an amended PAS and publicized in Update Standards). It was due for an update in early 2015 (Published in Feb. 2013). Some of the referenced documents are also out of date or withdrawn (e.g. PAS 55:2008).

Volumes Are only part of the Answer:   Clause 7.9 encourages the use of Volume Strategies to facilitate the coordination and clash avoidance approach. It states: “All members of the design team shall agree on volumes as fully as possible at the start of a project and publish them as a shared document.” Building coordination is a complex and dynamic area and how much emphases is placed on Volumnes, will depend on the scale, verticality and complexity of the project. Identifying building Core and Riser strategies during Stage 2 will be essential in some buildings, not in others. Volumes could be engaged to identify façade zone allocation in a multi-storey building. 

However, Volumes have various shortcomings. The transition from vertical to horizontal service route reticulation are generally the problem areas. Services reticulation in ceiling voids are also very dynamic, with different services requiring very different needs, even within the same discipline (e.g. gravity fed hydraulics vs. hot and cold domestic supply).  Generating 2D corridor ceiling void services diagrams / sections can define a planning strategy, which can be altered locally. Trying to do this in a 3D volumetric space early in the project are overly complicated. It is often not until halfway through Stage 4, that certainty of the building services reticulation is available. Alternatively, I have seen inexperienced participants, try to provide an entire horizontal ceiling void band per discipline. This leads to inefficient ceiling voids and substantial additional costs in the additional façade area required.

Bottom line – designers require a lot more tools than just 3D Volumes to coordinate buildings. It is just one tool of many.

Require Further Coordination Tools:   Interdisciplinary spatial coordination is one of the biggest challenges on the project. Clash detection is a very inefficient reactive method of coordinating, and is really suited better for fine tuning. Clash avoidance strategies and upfront planning deliver far greater efficiencies. It’s a shortcoming of the UK BIM Level 2 frameworks that it did not publish greater detail on coordination methodologies. With IFC likely mandated for BIM Level 3a, it would be disappointing if BIM Level 3a software’s were not required to meet agreed BCF (BIM Collaboration Format) minimum standards. I believe with the UK BIM Level 3 funding, there is real value in expanding the current scope BCF version 2, to extend across all major communication mediums in the industry, enabling a single source of tracking design and construction issues.  This may include 2D PDFs and MS Excel data sheets.

Contractors short changed:   The document is very Client and Designer centric. There is not a huge amount of information on the interactions with the contractors and sub-contractors.

The COBie delivery is very vague:  None of the actual COBie supporting documents (e.g. The COBie Guide) is referenced. It’s unclear if it is considered applicable. The approach also appears to overstep the intended use of COBie. According to Bill East (A primary author of the COBie schema):

"COBie should (only) include 'Managed' assets. Managed assets are those assets which;
-          requires management,
-          requires (considerable) on-going maintenance,
-          has consumable parts requires regular periodic inspections",

However, the UK Level 2 approach uses COBie as a primary Information exchange to include the Facility as a whole, and its constituent locations and Components. PAS 1192-2 only refers once to “Managed Asset” on the Annex A definitions section. PAS 1192-3 never mentions it.

There is a COBie Information Exchange (data drop) at the end of Stage 1, 2 & 3 (S6 Suitability) and at the end of Stage 6 (S7 Suitability - AIM), What happens during Stage 4 and 5 is anyone’s best guess. The BIM Task group created a “COBie Data Drops Structure, uses & examples” document but it’s not referenced anywhere in PAS 1192-2 or BS 1192-4 documents.

Object naming for UK COBie 2012 comes from BS 8541-1. It sets out two ways of naming objects. Covered in sections 4.3.2 and 4.3.3. Questions have been raised if this naming convention is appropriate for COBie. Recommended COBie naming is covered in the omitted “COBie Guide”. In all the UK COBie 2012 documentation, the one critical item omitted; COBie named components should match exactly what was tagged on the As-built 2D PDF drawings.

Lacking Definitions:   PAS 1192-2 contains a “Terms and Definitions” chapter at the start, for terms used within. It then is repeated at the back, “Annex A (informative) Terms, definitions and abbreviations for BIM documentation”, but also has additional terms added which are BIM/CAD-relevant. There are many acronyms and terms in PAS 1192-2 which are not explained, and these will cause readers much confusion, especially if you are not intimate with the UK Construction industry. Bear in mind, the UK Government sees this PAS as a stepping stone to an International Standard, ISO. It needs to be understood by all readers, irrelevant of geographical location.

As-Constructed deficiencies:   The site as-constructed verification process is a bit wishy-washy and it is possible it contains a lot of wasted work. While PAS 1192-2 is one of the more advanced documents on generating As-constructed models and documents, it still needs work. Refer to my earlier post on LOD 500 and As-builts.

Plan of Works and the BIM Toolkit:

Plan of Works:   The BIM Toolkit’s Digital Plan of works has not been taken up very well by the industry to date. Many say the tool does not provide the industry with the flexibility which is required. The CIBSE Journal published a detailed critical article on it here in November 2015.

Questionable LOD/LIA definitions:   There are some odd requirements identified in the BIM Toolkit Definitions:

LOD2: Requirement:
Graphical representation of element, dimensionally inaccurate. Purpose of information: To provide a visual indication of proposals at a Concept stage identifying key requirements such as access and maintenance zones etc.  Information to be suitable for zonal spatial coordination of primary systems / elements.
At concept design stage, a paint finish would only be generally called-up on external elevations. Room Data Sheets may contain some Paint finish information. What access and maintenance zones have to do with paint, I don’t know.
LOI6: Provide the information specific to the installed deliverable that is required for operation and maintenance. Information covering the detailed maintenance should also be provided in the associated PDF manuals.

Asset type
An indication of whether the object is fixed or movable.
Email address for the organisation responsible for supplying or manufacturing the object
The product, item or unit number assigned by the manufacturer of the object.
Warranty guarantor (parts)
Email address for the organisation responsible for the parts warranty.
Warranty duration (parts)
Duration of parts warranty.
Warranty guarantor (labour)
Email address for the organisation responsible for the labour warranty.
Warranty duration (labour)
Duration of labour warranty.
Warranty duration unit
Duration of warranties (typical value is 'years').
Replacement cost
An indicative cost for unit replacement.
Expected life
The typical service life of the object.
Duration unit
Duration of expected life (typical value is 'years')
Warranty description
Description of the warranty content and any exclusions.
Nominal length
Typically the larger or primary horizontal dimension.
Nominal width
Nominal width of product, typically the characteristic or secondary horizontal or characteristic dimension.
Nominal height
Typically the vertical or secondary characteristic dimension.
The name of the object as used by the manufacturer.
Characteristic shape of product.
Characteristic size of product.
Characteristic or primary colour of product.
Characteristic or primary finish of product.
Standard grading which the product corresponds.
Characteristic or primary material of product.
Optional constituent features, parts or finishes.
Other important characteristics or features relevant to product specification.
Accessibility performance
The accessibility issue(s) which the object satisfies.
Sustainability performance
Description of the sustainability issue(s) which the object satisfies
Code performance
The code compliance requirement(s) which the object satisfies
Serial number
The serial number assigned to an occurrence of a product by the manufacturer (per instance).
Installation date
The date that the manufactured item was installed (per instance).
Warranty start date
The date on which the warranty commences.
Tag number
The tag number assigned to an occurrence of a product by the occupier (per instance).
Bar code
The identity of the barcode (or RFID) given to an occurrence of the product (per instance).
Asset identifier
The identification assigned to an asset that enables its differentiation from other assets.

How can you ask for the above information for Paint? Are they kidding? This rhetoric is carried into Carpet, Pinboards, Concrete beams, etc. etc. So according to the BIM Toolkit every element in a building needs a Barcode, Asset Identifier, etc. It is clear some of these definitions need more work.


Linking Progression to Stages:   Sounds simple, however, some might say the UK Level of Definition approach is oversimplified and every project is different with unique areas which require more design and development over other areas. This statement may well have some truth; however, Level of Definition can be seen as a minimum development level. All projects, irrelevant of type or size should reach this defined progression by the end of the stage. Where projects contain specialized areas, which requires additional resolution over the traditional design stage, this can be determined by the design team in the plan of works.

Known entities:   Another comment which might be stated; the Client knows exactly what is to be installed, and may have details for it all ready. “Why can’t we assign that a higher Level of Definition at an early stage?”. This definitely occurs in many situations, however, the known element will only be one part of an entire Building System. It will always need to be tested against the design and engineering requirements. Allocating it a higher LOD over the planned stage does not provide any benefit to the Project team, and also is going against the principals of Lean.


Right Direction:   The UK MPS frameworks approach within the BIM Level is definitely a step in the correct direction. I believe many areas requiring improvements identified above are not insurmountable, and can be rectified. If it was not for the BIM Level 2 funding budget running dry, a lot of the inconsistencies, I believe would have been ironed out, and the resultant framework would be considerably more robust. It is difficult to see how a project can comply with every clause in PAS 1192-2. Will that mean they are not a BIM Level 2 Project? Why have a standard framework, if we can’t comply with it?

Outcomes versus Prescriptive:   Every supplier will always favour outcome based deliverables. Employers will in an age where the deliverables are new to the industry, it will favour prescriptive. BS1192 & BS1192-4 are 100% prescriptive. PAS1192-2 are both. Unfortunately, in this early stage of new BIM Maturity environments, prescriptive weighted approaches are inevitable. I believe the correct balance has been achieved. This, however, must continue to be highly scrutinized with the transition to outcome-based at the earliest opportunity.

Comparison:   I know many will be interested in how does the UK BIM Level 2 frameworks stack-up against the AIA Level of Development. They both have problems which need addressing. What I would say is the AIA Level of Development framework is based on some principles, which I believe are fundamentally incorrect (see my former article: LOD – the biggest BIM con to date!), and cannot be resolved.  Thus, the UK BIM Level 2 frameworks just comes out on top.

Not useable outside BIM Level 2:   Would I utilize the UK Level 2 MPS if I had the option? The bottom line, it is only applicable, if the project has a Level 2 BIM deliverable within the UK. So No. Some might try to engage the Level of Definition as a patch to replace the AIA’s G202TM’s Level of Development, and whereas this may be advantageous at Design stage, during construction it will fail, following the identified deficiencies in LOD5 above.

The Future: The BIM Task Group has now received substantial funding to strive for Level 3 BIM.  This will involve four progressive stages from Level 2 to level 3 (a, b, c & d). The first one, 3a, will include improvements to the current Level 2 and the incorporation of the IFC file format as a deliverable. BS 1192 and PAS 1192-2 are in the process of being upgraded to ISO 19650-2 (further information here). With the combination of all of these developments, hopefully in the future, we can look more favorably at the UK Level 2 MPS frameworks.

Part 2 is here. It is a detailed run down through exactly how the UK BIM Level 2 MPS works. All references are included in Part 2. I encourage comments and discussion below.


  1. I like this post and the detail included. I disagree with the above statement "yet, the sample MPDT does not mention models. It only identifies supplier / authors, the Level of Detail and stage delivery"

    The MPDT does in fact relate to models not suppliers.
    examples include, "Space planning model" is having a model capable of portraying space.
    "Structural", under "performance" means that a model containing structural performance is required.
    "Fire" under "design strategies" means having a model that contains fire strategy information.
    And "Building" under "Elements materials" means that the building fabric containing elements is to be delivered. Whereas "building" under "performance" is a different type of requirement albeit could be within the same model.

    I like to think of the MPDT as a specification for models and its outcomes i.e what you can do with the model.

  2. Thanks John for your comments. I’m very glad you liked the post.

    I find your explanation very interesting. It is clear the MPDT requires greater explanation and better wording within the documentation.
    Thanks again.

  3. Hi Brian, really really missing good quality - real life, MPDT here. I assume that unlike the NBS toolkit, and the sample shown above ,we could have data drops, say per costing stages that sit between Plan of Work stages - which could then also be given their own LO-Defintion with changing LO-Model Detail and LO-Information. This makes sense to me as there are many intermediate drops that need the BIM data to be statused under a LO-Definition. The design team needs to be clear here on what is the expectation from them on those drops (obviously). What do you think? And you have seen a better MPDT around your neck of the woods, or even a great task information delivery plan - which should have the same kind of content as a MDPT anyway (no?). Thanks for thoughts - feeling like I'm progressing on this topic now :) Many thanks for the blog here - pure gold.

    1. Hi David
      Thanks for your comments.
      From my understanding of the RIBA Plan of works, there is no drop between stages typically. I believe the drops (Exchanges) you refer to are at the end of the stages. The exact point in time of when one stage finishes and one starts are always a little blurred.
      With some of the alternative examples of MPDTs, they look a lot more like a Model Element Matrix Table. Have a look at some of the other EIR examples I linked to.
      Cheers Brian

    2. Thanks Brian.
      The initial conclusion I get to here is that the BIMforum LO-Development spec starts to look compelling. I spoke to a NZ engineering company today - who are implementing globally BS1192 etc + AIA LOD. I can see how this works now - as the MPDT in Level2BIM can simply be the AIA defined Model Element Table which uses UniClass and BIMforum LOD spec - all of which can be appended to UK protocols. This seems feasible.
      Latest BIMforum spec (these guys are now the US Building Smart Chapter) takes account of attributes as Marzia mentioned (ie close to the Level of Information in NBS Toolkit Level of Definition approach) so it' pretty covered.
      And as we've established stages of works as data drops is not set in stone - many intermediate stages can be defined. This seems to work better with how companies in my travels say they send multiple versions of models within a stage.
      What do you think?


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