articles about bim

8/10/2019 Articles about BIM

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BIM levels explained - Building Information Modelling (BIM) article from NBS

BIM levels explained

The concept of BIM levels (and BIM level 2 compliance) has become the accepted definition of what

criteria are required to be deemed BIM-compliant, by seeing the adoption process as the next steps in a

journey that has taken the industry from the drawing board to the computer and, ultimately, into the digital

age.

The government has recognised that the process of moving the construction industry to full collaborative

working will be progressive, with distinct and recognisable milestones being defined within that process, in

the form of levels. These have been defined within a range from 0 to 3, and, whilst there is some debate

about the exact meaning of each level, the broad concept is as follows:

Level 0 BIM

In its simplest form, level 0 effectively means no collaboration. 2D CAD drafting only is utilised, mainly for

Production Information (RIBA Plan of Work 2013 stage 4). Output and distribution is via paper or electronic

prints, or a mixture of both. The majority of the industry is already well ahead of this now (source: NBS

National BIM Report 2014).

Level 1 BIM

This typically comprises a mixture of 3D CAD for concept work, and 2D for drafting of statutory approval

documentation and Production Information. CAD standards are managed to BS 1192:2007, and electronic

sharing of data is carried out from a common data environment (CDE), often managed by the contractor. This

is the level at which many organisations are currently operating, although there is no collaboration between

different disciplines each publishes and maintains its own data.

Level 2 BIM

This is distinguished by collaborative working all parties use their own 3D CAD models, but not necessarily

working on a single, shared model. The collaboration comes in the form of how the information is exchanged

between different parties and is the crucial aspect of this level. Design information is shared through a

common file format, which enables any organisation to be able to combine that data with their own in order

to make a federated BIM model, and to carry out interrogative checks on it. Hence any CAD software that

each party used must be capable of exporting to one of the common file formats such as IFC (IndustryFoundation Class) or COBie (Construction Operations Building Information Exchange). This is the method of

working that has been set as a minimum target by the UK government for all work on public-sector work, by

2016.

Level 3 BIM

Currently seen as the holy grail, this represents full collaboration between all disciplines by means of using a

single, shared project model which is held in a centralized repository. All parties can access and modify that

same model, and the benefit is that it removes the final layer of risk for conflicting information. This is known

as Open BIM, and the UK governments target date for public-sector working is 2019? Current nervousness

in the industry around issues such as copyright and liability are intended to be resolved the former by

means of robust appointment documents and software originator/read/write permissions, and the latter by

shared-risk procurement routes such as partnering. The CIC BIM Protocol makes provision for these.

Looking further ahead, it is highly probable that collaborative working practices will

ultimately filter through to the private sector ...

What thi s means in practice

The significance of these steps, in real terms, is that UK government has adopted this definition in its

Construction Strategy, by requiring that all publicly -funded construction work must be undertaken by using

Building Information Modelling to Level 2, by 2016. This mandate has been set as one measure to help in

fulfilling their target of reducing waste in construction by 20%. It is considered that abortive work,
http://www.thenbs.com/pdfs/NBS-National-BIM-Report-2014.pdfhttp://www.thenbs.com/pdfs/NBS-National-BIM-Report-2014.pdfhttp://www.thenbs.com/pdfs/NBS-National-BIM-Report-2014.pdfhttp://www.thenbs.com/pdfs/NBS-National-BIM-Report-2014.pdf


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The 20 key BIM terms you need to know - Building Information Modelling (BIM) article from NBS

The 20 key BIM terms you need to know

With the sheer volume of new technical terms and keywords being used in connection with BIM, the average

construction industry worker could be forgiven for being confused by the jargon. With that in mind, the

following is a list of the 20 need-to-know BIM terms, and their definitions.

1. 4D, 5D, 6D

First there was 2D CAD, then 3D CAD now there are extra dimensions to refer to the linking of the BIM

model with time-, cost- and schedule-related information (although the precise order hasnt to date been

agreed across the whole industry).

2. Asset Information Model (AIM), Building Information Model (BIM), Project

Information Model (PIM)

Not only is there the Building information model, but the Asset information model which is the name given

o the same model post-construction, i.e. supplemented with the data needed to assist in the running of the

completed asset. Note that asset can also refer to civil engineering and infrastructure work (see also

Uniclass, below).

Conversely, the Project information model is the name given during the design and construction stage, i.e.

whats commonly known as the project among the design team.

3. BIM execution plan (BEP)

PAS 1192-2 (see below) proposes that a BIM Execution Plan is created for managing the delivery of the

project. This in turn is split into a pre-contract BEP, in response to the Employers Information Requirements

(in other words, comparable to contractors proposals in a Design & Build contract) and a post-contract

BEP which sets out the contracted delivery details.

4. CIC BIM protocol

A supplementary legal agreement which is designed to be used by construction clients and contractor clients.

It is incorporated into professional services appointments and construction contracts an amendment to

standard terms, creating additional rights and obligations for the employer and the contracted party to

facilitate collaborative working, while safeguarding intellectual property ownership and liability differentiation

between those involved.

5. Clash rendition

Referred to in PAS 1192-2, rendition of the native-format model file is be used specifically for spatial

coordination processes. Used to achieve clash avoidance or for clash detection (between, for example

structure and services) between Building Information Models prepared by different disciplines. The key

benefit is in reducing errors, and hence costs, pre-construction commencement.

6. Common Data Environment (CDE)

This is a central information repository that can be accessed by all stakeholders in a project. Whilst all the

data within the CDE can be accessed freely, ownership is still retained by the originator. Cloud storage is a

popular method of providing a CDE, although it could also be a project extranet. The scope and requirements

for a CDE are defined in PAS 1192-2 (see below).

7. Construction Operations Building Information Exchange (COBie)

COBie is a data schema which is delivered in a spreadsheet data format, and contains a subset of the

information in the building model (all except graphical data, and hence a subset of IFC; see below), for FM

handover. It was originally devised by the US Army Engineering Corps. Over the course of a project, data

can be added to it from a range of sources (besides CAD programs), relating to brief, design, construction,


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standard (see below).

9. Data Exchange Specification

A specification for electronic file formats that are used for the exchange of digital data between different BIM

software applications, thereby facilitating interoperability. Examples include IFC and COBie (see above). PAS

1192-2 outlines information exchange activities.

10. Federated model

This is, in essence, a combined Building Information Model that has been compiled by amalgamating several

different models into one (or importing one model into another; i.e. collaborative working). For example, an

architect can import a structural engineers model data into their spatial model. This is the basis of the UK

governments Level 2 BIM mandate, whereas Level 3 will result in all stakeholders working on one shared

model (integrated).

11. Government Soft Landings (GSL)

A UK government-initiated handover protocol to champion better outcomes for built assets during the design

and construction stages. Its objective is to reduce costs (capital and running) and improve performance of

asset delivery and operation, and can be assisted through the use of a Building Information Model. Two

notable features are that:

BIM is intended to be used increasingly as a data management tool to streamline the briefing process

Post Occupancy Evaluation is carried out, to measure and optimise performance of the asset, and learn

lessons for the future.

12. Industry Foundation Class (IFC)

IFC is an object-based format, to enable exchange of information between different software. Developed by

buildingSMART, a global alliance specialising in open standards for BIM, IFC is an official standard, BS ISO

16739, and contains geometric as well as other data.

13. Information Delivery Manual (IDM)

To make BIM effective, information needs to be:

made available when it is needed and

to a satisfactory quality.

This can be achieved by using an Information Delivery Manual, that identifies the various construction

processes, and the information required at each stage. ISO 29481-1 specifies a methodology for the format

of the IDM.

IDM also forms one part of the BuildingSMART interoperability model; the other two parts being the Data

Dictionary (mapping alternative terms for common elements) and IFC (see above). Note that this is beyond

he scope of Level 2 requirements.

14. Information Manager

The CIC BIM Protocol (see above) refers to and provides for the appointment of an Information Manager by

he employer. This is, in essence, a project manager, who is responsible for managing the delivery of the

asset using BIM procedures and methods. This is expected to form part of a wider set of duties under an

existing appointment and is likely to be performed either by the Design Lead or the Project Lead.

15. Level 0 BIM, Level 1 BIM, Level 2 BIM, Level 3 BIM

The move to full collaborative working via distinct and recognisable milestones, in the form of levels. These

have been defined within a range from 0 to 3, and, whilst there is some debate about the exact meaning of

each level, the broad concept is:


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Complexes or collections of buildings such as a university campus or an airport

Entities, which comprise individual buildings

Activities taking part within different parts of those buildings

Spaces, or rooms

Elements such as walls, floors and ceilings

Systems, for example door and window systems, or wall lining systems

Products such as sheet materials, or fixings.

Uniclass is more sophisticated than the Common Arrangement of Works Sections (CAWS), in that:

it encompasses the entire life cycle of a built asset

it can cater for assets of any scale, so can be used for planning as well as design and construction

it can accommodate infrastructure and civil engineering projects, in addition to buildings.

Note that a revised version of Uniclass is currently in development as part of the BIM Toolkit project (see

above), to improve table alignment for mapping.

Useful links

BIM in Small Practices: Illustrated Case Studies, Robert Klaschka, NBS

BIM for the terrified

BS 8541-3Library objects for architecture, engineering and construction. Shape and measurement

code of practice, 2012

BS EN ISO 14040:2006Environmental management. Life cycle assessment. Principles and framework

BS ISO 12006-3:2007Building construction. Organization of information about construction works.

Framework for object-oriented information

BS ISO 16739:2013Industry Foundation Classes (IFC) for data sharing in the construction and facility

management industries

BS ISO 29481-1:2010Building information modelling. Information delivery manual. Methodology and

format

BuildingSMART

CIC BIM Protocol

CPIC

Government Construction Strategy(2011)

NBS BIM Toolkit

NBS National BIM Report 2014

PAS 1192-2 -3Specification for information management for the capital/delivery phase of construction

projects using building information modelling

RIBA Plan of Work 2013

December 2014

by Anthony Lymath, Architect/Technical Author, NBS
http://www.thenbs.com/resources/articles/index.asphttp://www.thenbs.com/resources/articles/index.asphttp://www.ribabookshops.com/item/bim-in-small-practices-illustrated-case-studies/80471/http://www.thenbs.com/BIM-FM/download.asphttp://www.thenbs.com/publicationindex/DocumentSummary.aspx?PubID=76&DocID=302011http://shop.bsigroup.com/ProductDetail/?pid=000000000030154435http://shop.bsigroup.com/ProductDetail/?pid=000000000030094640http://shop.bsigroup.com/ProductDetail/?pid=000000000030279850http://shop.bsigroup.com/ProductDetail/?pid=000000000030279850http://shop.bsigroup.com/ProductDetail/?pid=000000000030181567http://www.buildingsmart.org/http://www.thenbs.com/topics/BIM/articles/www.cic.org.uk/download.php?f=the-bim-protocol.pdfhttp://www.cpic.org.uk/https://www.gov.uk/government/publications/government-construction-strategyhttp://www.thenbs.com/bimtoolkit/http://www.thenbs.com/topics/BIM/articles/nbs-national-bim-report-2014.asphttp://shop.bsigroup.com/en/forms/PASs/PAS-1192-2/http://shop.bsigroup.com/en/forms/PASs/PAS-1192-2/http://www.ribaplanofwork.com/http://www.addthis.com/bookmark.phphttp://www.ribaplanofwork.com/http://shop.bsigroup.com/en/forms/PASs/PAS-1192-2/http://www.thenbs.com/topics/BIM/articles/nbs-national-bim-report-2014.asphttp://www.thenbs.com/bimtoolkit/https://www.gov.uk/government/publications/government-construction-strategyhttp://www.cpic.org.uk/http://www.thenbs.com/topics/BIM/articles/www.cic.org.uk/download.php?f=the-bim-protocol.pdfhttp://www.buildingsmart.org/http://shop.bsigroup.com/ProductDetail/?pid=000000000030181567http://shop.bsigroup.com/ProductDetail/?pid=000000000030279850http://shop.bsigroup.com/ProductDetail/?pid=000000000030094640http://shop.bsigroup.com/ProductDetail/?pid=000000000030154435http://www.thenbs.com/publicationindex/DocumentSummary.aspx?PubID=76&DocID=302011http://www.thenbs.com/BIM-FM/download.asphttp://www.ribabookshops.com/item/bim-in-small-practices-illustrated-case-studies/80471/http://www.thenbs.com/resources/articles/index.asphttp://www.thenbs.com/resources/articles/index.asp


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The top five barriers to BIM implementation - Building Information Modelling (BIM) article from NBS

The top five barriers to BIM implementation

In the move to comply with the UK governments mandate to work to BIM Level 2 by 2016, organisations are

likely to encounter challenges in the process. Time and capital need to be invested, and smaller

organisations in particular will view the implementation of BIM with trepidation. Whats more, the construction

industry as a whole lacks clarity on the issue, and there will be a common perception that BIM is the preserve

of the larger organisation rather than the smaller.

The NBS National BIM Report 2014identified the top five reasons cited by those organisations who havent

yet made the move; these are outlined below.

1. No client demand

This was cited by 73% of practices employing five staff or fewer. Whilst the Government is in the process of

enforcing BIM for publicly-funded work, clients of smaller organisations dont often make similar demands

and the smaller they are, the less likely this is.

2. Not always relevant to projects worked on

71% of small practices (five or fewer staff) felt that BIM simply isnt applicable, or appropriate, to the nature

of their typical workload. They may feel that there isnt the level of complexity to warrant BIM, but the fact is

hat even domestic projects can be complex.

3. Cost

A common observation was the need to get through the downturn before looking at BIM. The recession has

increased cautiousness, particularly when it comes to financial outlay. And it cant be denied that the move

does involve expenditure on software, training, and time. But the costs need to be weighed against the

potential benefits. Those who have adopted BIM tend to report that the experience has been better than they

had anticipated.

4. Projects worked on perceived as too small

Contrary to common perception, BIM can work on any size of project from a domestic refurbishment upwards

the biggest inhibitor to its effectiveness is the quality of the survey undertaken, but this is in fact the caseregardless of whether a building is drawn in 2D or 3D. Although small contractors are likely to provide

resistance to technological changes in working practices initially, the workplace is nevertheless evolving all

he while, and the benefits can still be realised during the earlier stages of a project in the meantime.

5. Lack of in-house expertise

62% of practices with five or fewer staff expressed this concern, and 77% of practices with six or more staff.

Although organisations particularly smaller practices may not currently have the skills in-house, the

upturn in the industry is leading to an increase in recruitment, and this is the ideal time to recruit staff with thenecessary skills. Savvy employees will have upskilled during the recession, and smaller practices can be

more agile in their response to and adoption of BIM by being able to take advantage of lower aggregate

raining costs.

Conclusion

Despite any reluctance to make the change, organisations can take comfort from the fact that only 4%

wished that they hadnt adopted BIM. More importantly perhaps, 61% of users found that BIM brought cost

efficiencies, 52% that it increased the speed of delivery and only 16% didnt feel that it had increased

profitability.

Of organisations that havent yet adopted BIM, 59% believe they will be left behind if they dont do so. With

unremitting pressure on architects and others professional fees, it looks as if BIM may offer a way to getting

more work, and making that work more profitable.

The experience of those who have adopted BIM shows us that the process whilst not easy is worthwhile IFC - is it simply misunderstood? - Building Information Modelling (BIM) article from NBS
http://www.thenbs.com/topics/BIM/articles/nbs-national-bim-report-2014.asphttp://www.thenbs.com/topics/BIM/articles/nbs-national-bim-report-2014.asphttp://www.thenbs.com/topics/BIM/articles/nbs-national-bim-report-2014.asp


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IFC - is it simply misunderstood? - Building Information Modelling (BIM) article from NBS

http://www.thenbs.com/topics/BIM/articles/IFC-is-it-simply-misunderstood.asp[6/01/2015 10:46:24]

IFC is it simply misunderstood?

by Stefan Mordue

NBS Technical Author

The issue of interoperability is becoming more apparent as we begin to use more pieces of software, but how

we integrate information has always sparked commentary and divided opinion.

BIM is more than just technology, but perhaps it is the development in the transfer of digital information that

is providing the impetus missing in previous construction industry initiatives, such as the responses to the

Latham and Egan reports. To achieve BIMs full potential we require a robust mechanism to exchange the

ever increasing levels of digital data, regardless of what software package or BIM platform is used.

Essentially speaking, IFC provides the guidelines or rules to determine what information is exchanged.

Although it may include geometry, it is not limited to this; it presents tangible building components such as

walls and doors and also enables the linking of alphanumeric information (properties, quantities,

classification, etc.) to building objects and maintaining these relationships.

What is information exchange?

IFC is an industry-wide open and neutral data format that is fast becoming the de-facto standard for rich data

exchange. It was first developed by an industry consortium formed by Autodesk in 1994 and known as the

Industry Alliance for Interoperability. To assist the development of a non-proprietary standard it was renamed

he International Alliance for Interoperability in 1997 and reconstituted as a not-for-profit alliance. It promotes

IFC as a neutral product model supporting the building lifecycle and opens up membership to all interested

parties.

Model View definition

Since 1996 there have been six principal schema releases, IFC1.5.1, IFC2.0, IFC2x, IFC2x2, IFC 2x3 and

IFC4. (Formally known as IFC 2x4). BuildingSMART recommends that at this moment in time, IFC 2x3 is the

best choice to implement as it has the broadest coverage of support of all published IFC releases. However

now IFC4 is registered with ISO as an official International Standard, ISO 16739:2013 it is hoped that

software vendor implementation will increase.

For further information on currently certified software and the software certification scheme, see the

buildingSMART website.

In order to satisfy the many information exchange requirements of the AEC Industry, a Model View

Definition (MVD) defines a section or subset of the IFC schema for particular uses. For example, the COBie

spreadsheet is a mapping of the FM Basic Handover MDV, which includes operational information. Other

MDVs for 2x3 include the Coordination View and the Structural Analysis View.

Combined data

At NBS we are passionate about information. Information needs to be authored once, and in the right place

but with BIM we now have the added benefit that we can report it many times. With the development of our

NBS plug-in tools,BIM objects are becoming placeholders, connecting to a wider and richer source of

information, and providing this with relevant guidance at the point in time it is required .

Since data is coming from a variety of sources, we need to be able to report and collate it in one central

depository. Working alongside Professor Steve Lockley at the BIM Academy, the NBS Software development

eam have been generating a set of components that read and write to and from IFC. Currently in beta

format, they have the ability to link key property sets together between the geometric model and the

specification, producing an IFC file that contains the combined information.

Exchange Schema

IFC - is it simply misunderstood? - Building Information Modelling (BIM) article from NBS
http://www.buildingsmart.org/certification/certification-of-softwarehttp://www.thenbs.com/topics/BIM/videos/developing-software-BIM-UK.asphttp://www.thenbs.com/topics/BIM/videos/developing-software-BIM-UK.asphttp://www.thenbs.com/topics/BIM/articles/aPicturePaintsThousandWords.asphttp://www.thenbs.com/topics/BIM/articles/aPicturePaintsThousandWords.asphttp://www.thenbs.com/topics/BIM/videos/developing-software-BIM-UK.asphttp://www.buildingsmart.org/certification/certification-of-software


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IFC is it simply misunderstood? Building Information Modelling (BIM) article from NBS

http://www.thenbs.com/topics/BIM/articles/IFC-is-it-simply-misunderstood.asp[6/01/2015 10:46:24]

As the saying goes, it takes two to tango, and is worth noting that as a schema, IFC itself cannot provide

interoperability, rather it relies on the software packages interfacing with it. The schema often sparks debate

and criticism in that it sometimes drops data or loses geometry, but is this due the IFC standard or how it is

being implemented? Further limitations currently exist around IFCs ability to contain parametric information

and manipulate the size of an object, however IFC4 and subsequently future releases look to address this.

Today, most modern BIM authoring platforms support import and/ or export of IFC model data, with

buildingSMART issuing official certification to applications that comply with consistent procedures. This flow

of information is critical for collaboration and interoperability, as it allows use between different authoring and

downstream applications, e.g. facilities management, structural modelling and analysis applications.

ith the 2016 Level 2 BIM deadline date fast approaching, the construction industry is getting to grips with

he Open Standard data format set by the Government, the Construction Operations Building information

exchange (COBie) data schema. COBie allows information about buildings to be organized, documented and

shared in a standardized way. In association with the Open BIM network, NBS wanted to test whether the

buildingSMART IFC file format was capable of supporting the creation of COBie datasets. We did this by

running a trial with the help of a number of Tier 1 contractors. The free IFC/ COBie Report 2012is available

o download from theNBS.com. As a follow on to this trial, the OPEN BIM Network (which merged with

buildingSMART UK to form a User Group) in partnership with the BIM Academy, defined a further series of

COBie field trialsusing live models provided by Gatwick Airport Ltd.

Best of Breed

Open BIM is more than just IFC, it is a commitment to open standards and engagement. It allows both small

and large platform software vendors to participate and compete on system independent, best of breed

solutions. Any vendor with similar strategies can participate, even competing products and so the attraction of

Open BIM is that consultants can join workflow without giving up their BIM tool which they are familiar where

hey may have otherwise been essentially excluded from a project. In the past interdisciplinary collaboration

have taken advantage of Xrefing each others 2D drawings with coordination being managed by manual

update changes. Clearly, complex 3D elements need a more robust level of co-ordination and so Open BIM

uses a reference model concept. Using this approach is perhaps as much about a new mind set than

anything else as it requires a strict regime of classifying elements correctly in order that information can be

filtered and exchanged. It is unlikely that the receiving party will require the full BIM so by appropriately

classifying elements using IFC classification headings, only the relevant elements and information are sent to

he other party.

Open Exchange

The proprietary data format that is particular to a BIM software vendor can be quickly, reliably and efficiently

updated and adapted to suit a changing market. However, the conundrum here is that in the long term they

will prove to be expensive to maintain and support if they do not support a shared approach to data

exchange, the very ethos of BIM. I am sure we have read the analogy of Beta Max vs VHS to BIM software

formats over and over again. VHS, the eventual winner, gained a dominance in the market that for almost 20

years, but the format received little development. And we really do not want that for the construction industry.

Open exchange standards are not new and started to emerge as early as the late 1970s following

agreements between the leading CAD vendors and users. In the mid-1980s the Standard for Exchange ofProduct (STEP) model was developed as it was considered at that time that none of the existing formats, on

heir own, could support the needs of an open standard across multiple industries. However, STEP was

considered too slow and unresponsive to meet upcoming market need in the construction industry and so

motivation started to develop for a separate standard for the architecture, engineering and construction (AEC)

and facilities management (FM) industries.

Does IFC really deserve the criticism it receives or is it simply misunderstood? Answers on a post card,

please.

Related NBS information
http://www.thenbs.com/topics/BIM/cobie/index.asphttp://www.thenbs.com/topics/BIM/cobie/index.asphttp://www.buildingsmart.org.uk/openbim-cobie-field-trialshttp://www.buildingsmart.org.uk/openbim-cobie-field-trialshttp://www.buildingsmart.org.uk/openbim-cobie-field-trialshttp://www.buildingsmart.org.uk/openbim-cobie-field-trialshttp://www.thenbs.com/topics/BIM/cobie/index.asp

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