Building Information Modelling or ‘BIM’ is a technology platform that is capable of generating 3D model of building or infrastructure for the purposes of construction project. Such digital model is intelligent and data rich where parties involved in the lifecycle of such project e.g. architect, engineers, contractors, surveyors, facility managers, regulatory authorities etc could access project related information, modify or update such information to enable collaboration. Apart from an enhanced visualisation of the building prior to getting constructed, such technology platform provides granular insights into the spatial dimensions, inter disciplinary coordination, schedule and sequence of construction methodology, progress of works, cost and cashflow etc. Given that the possibilities are rather limitless, it is currently supported by various softwares available in the market including Autodesk Revit, Navisworks, AutoCAD etc.

This article examines BIM from the perspective of main contractors and subcontractors under traditional design-bid-build procurement pathway as it relates to disputes and claims. Under such traditional procurement arrangement, contractors do not have any design responsibility and are generally required to build in accordance with the drawings produced by the project consultants. Since contract sums are derived based on drawings and specifications issued during tender, any deviations from original design that entitles additional payment and/or extension of time are rather self evident by means of visual comparison with construction drawings produced by the consultants. With the increase in adoption of BIM in various construction projects, contractors are expected to ‘work collaboratively’ with other parties in the project such as consultants, Employer’s representatives and its stakeholders using the prescribed software or under an open BIM platform. Very often working collaboratively involve providing input to BIM models which may then be relied upon by other parties. What are the digital safeguards available for avoidance of implicitly undertaking design responsibilities? Since all stakeholders are working based on an agreed digital model as opposed to each party producing their respective 2D drawings, will this inadvertently compromise a clear delineation of responsibilities? 

It is not uncommon to see contractors hiring BIM managers, BIM coordinators etc to support their projects. However are these contractor appointed BIM representatives in the best position to safeguard the contractor’s contractual interest? What should contractors be mindful of in its participation of BIM projects such that they can harness the productivity benefits whilst being alert of any unintended consequences relating to claims and disputes? By way of example, contractors are often required to produce combined services drawings and shop drawings in the course of construction so as to ensure that the routing of services do not physically clash on site and that the actual site dimensions are identified prior to manufacturing of certain building components for site installation. To this end, BIM can be of great help in that clash detection and spatial coordinations can be done digitally through the relevant 3D models and software functions. However, the resolution of clashes in layout of services often involve design development decision making that may require compromises to be made to the original design. These compromises include change in size or location of building structural elements (e.g. beams, slabs, columns), increase in false ceiling space which result in reduction in floor to ceiling height, checks against design codes clearances to ensure continuing compliance etc. BIM softwares could be efficient in that a modification in one aspect of the design automatically updates all other elements of the building design that are affected. To what extent is the contractor authorised to make those design developments decisions under traditional arrangement? Are these changes considered alternative proposals from the contractor? What are existing provisions under standard conditions that deal with such scenario? Can the ‘no objection’ from the relevant consultants be deemed as a tacit entitlement to additional payment or time? Should the contractor be actively seeking an ‘instruction’ from the contract administrator to regularise such automated digital design change? 

In essence the queries above are clarifications on how to avoid blurring the distinction between design responsibility and construction responsibility with the increase in digital collaboration under BIM. It is interesting to note that despite the increase in use of BIM in construction projects, there is yet any BIM specific provisions under standard conditions of contract to provide clarity on some of these difficult issues. Notwithstanding that, there is a recommended set of BIM Particular Conditions (2nd version published in August 2015) led by Building And Construction Authority (BCA) and its appointed BIM Steering Committee that can be incorporated in contracts for BIM projects. As these recommended particular conditions do not cover all issues related to BIM, users are still required to review and adapt these recommended provisions for their specific needs. In the next few sections of this article, some of the subtle and complex considerations arising from the use of BIM will be explored further from the contractor’s perspective. These include how BIM could be used to facilitate claims management and also best practices to avoid unintended claims and disputes consequences. These discussions can help to better inform contractors in case BIM related particular conditions are to be negotiated and adopted for its needs.

Who Should Hire BIM Manager?

As alluded to earlier, increase in collaboration should not cause reduction in clarity of roles and responsibilities. There should be a system or execution plan in place to maintain a credible historical record of all versions of BIM models including chronological list of inputs contributed by different parties. In case of conflicts or discrepancies on the choice of BIM models that shall take precedence, there must be an agreed method of reconciling such differences where all parties agree to be bound and comply with any outcome of a common method of resolution. As mentioned earlier, the BIM Particular Conditions (version 2) include clauses that provide governance structure to some of these critical BIM management issues. In essence the effectiveness of such governance structure not just depend on the clarity of rules but it is equally important to have such rules administered and enforced by an appropriately authorised individual with the relevant gravitas and hierarchical stature. To this end, Clause 1.5 of the BIM Particular Conditions specified that a BIM Manager shall have such responsibilities and will be appointed by the Employer. According to Clause 2.6.3 of the BIM Particular Conditions, any discrepancies between conflicting models shall be reported to the BIM Manager who shall facilitate resolution of the discrepancy. Further, Clause 3.1 states that the Employer shall appoint one or more such BIM Manager of which all compensation and related cost shall be paid by the Employer. In order to ensure that the BIM Manager is empowered, Clause 4.4 states that in the event of any disagreements on the terms of the BIM Execution Plan, the BIM Manager’s decision shall be final and conclusive. The BIM Manager shall report to and keep the Employer informed on all matters relating to the BIM Execution Plan which shall be updated from time to time. 

The benefits of BIM can only be harnessed based on the extent to which its governance structure can be enforced. To this end, having an appropriately qualified and duly authorised BIM Manager are of paramount importance. It is important to note that therefore the question of who should hire BIM Manager is not merely an human resource and payroll related decision but rather a strategic contractual decision. By way of illustration, if a BIM Manager is reduced to a mere clerical or administrative position, the governance structure could not be enforced effectively potentially nullifying the purported benefits of implementing BIM system. This is why the BIM Particular Conditions had rightly dedicated a significant part of its provisions to ensuring that the Employer, arguably the party with the most bargaining power and commercial leverage to be involved in the appointment of a BIM Manager. This in turn should ensure that its consultants and designers are not relieved from their design responsibilities and do not in any way obfuscate their design obligations from the contractors’ construction obligations. To this end, Clauses 2.4.1 and 2.4.2 underscore such existing contractual arrangements. 

Therefore when main contractors or subcontractors engage or hire BIM related positions for their respective firms e.g. BIM Managers, BIM Coordinator, BIM Modeller, they should ensure that any such personnels do not conflict or contradict with the said BIM Particular Conditions. It is not uncommon to see contractors seeking to hire BIM Managers with responsibilities that are described as follows (1) develop and lead BIM strategy for project in hand, (2) facilitate collaboration between project team members including consultants and stakeholders, (3) conduct regular quality control checks to ensure BIM models meet project requirements and industry standards etc. Assuming these descriptions are intentional, it may potentially conflict with the said governance structure that has been put in place by the BCA and its BIM Steering Committee. It should be noted that much of the BIM related modelling works and its governance set up are already in place prior to the appointment of main contractor and subcontractors. As an example, based on Circular issued jointly by BCA and Urban Redevelopment Authority (URA) dated 1 February 2023 (circular no: URA/PB/2023/01-DCG) all regulatory submissions made from June 2023 onwards shall progressively be required to be done through BIM format. In particular, new projects with Gross Floor Area exceeding 5000 m2 will need to use the openBIM standard. Therefore, the BIM is adopted for project in hand much earlier than any BIM Manager that may be hired by the main contractor. It is highly unlikely that such BIM Manager can belatedly put in a place a BIM execution plan and agree on BIM project standards retrospectively after its adoption months or even year earlier. It is never a wise strategy to put the cart before the horse. If the contractors are required to hire BIM personnels as part of their tender requirements, there should be clarity in scope of services such that the contractors are not expected to bite off more than what they can chew.

Detailed Design That Are Free Of Clashes/ Conflict In Layout of Services With Accurate Site Dimensions

BIM offers a potential breakthrough of a perennial problem that relates to contractors’ entitlement to accurate detailed design particularly with site dimensions and well coordinated layout of services. By way of background under traditional design-bid-build contract, the architect and engineer are required to provide the contractor with detailed design complete with dimensions and scale necessary for the contractors to proceed with its construction works. As an example, the SIA Building Contract 2016 specified under its Clause 3(2)(a) that the Architect shall further supply working drawings, specifications, details, levels or other information from time to time during construction period as may be necessary to amplify and explain in detail the works to be carried out by the contractor. Further, under Clause 19.1(d) of the PSSCOC (Eighth Edition July 2020), any change in the levels, lines, positions and dimensions of any part of the works shall deemed a variation. Therefore contract drawings from consultants should be provided with details and dimensions such that any difference from actual site condition is considered a variation. Notwithstanding that, it is also fairly common that contractors are often required to provide shop drawings prior to manufacturing of certain parts of the works where they are to verify actual dimensions and conditions on site prior to commencement of the works. It is also customary for the contractors to be required to include in its contract sum the cost of ‘wastages’ as a result of cutting of building supplies or finishes to accommodate the site conditions. Consequently, it is not uncommon for parties to dispute over which party should be responsible for the cost associated with ensuring that the actual works carried out on site conform with the site conditions. This situation is inherently vague because there are contract provisions that ‘by implication’ leaves any question of design, choice of material or workmanship to the contractors e.g. Clause 3(1)(a) of the said SIA Building Contract. 

Given the above, the risk allocation in respect of completeness of design details can be contentious and debatable. The ambiguity is exacerbated when contractors particularly those carrying out mechanical, electrical and plumbing works are often required to produce combined services drawings that coordinate the layout of services to ensure that these are free of conflicts or clashes in routing on site. Therefore, consultants regularly qualify that their design drawings merely communicate a set of performance based design intents that leaves the contractor with the latitude to comply these in any way it deems fit. However with the advent of BIM, 3D modelling appear to provide a digital solution to such perennial 2D problem. The Singapore BIM Guide (Version 2 dated August 2013) is drafted with joint collaboration of public sector and private enterprise partnership aims to provide clarity on the requirements of BIM usage at different stages of construction project. Whilst this document remains a ‘guide’, it is a useful document that sets out the standard practice and industry norm as it relates to roles and responsibilities for various project members when using BIM in a construction project. Contractors should therefore benchmark any tender conditions with the guidelines included in this document as a basis of negotiation. This guide apparently provide some instructive principles on the subject of site dimensions and coordination of layout of services. 

According to Architectural BIM Modelling Guideline included in Appendix C of the Singapore BIM Guide (Version 2), the modelling is structured in five distinct stages namely (a) Conceptual (b) Preliminary Design (c) Detailed Design (d) Construction (e) As Built. Under traditional design-bid-build pathway, contractors are generally responsible for stages after detailed design i.e. construction and as built. Under ‘Detailed Design’ where the output is for the production of tender documents, the general requirement is that all the architectural elements in the model uses actual or accurate dimensions and correct materials. Therefore, the tender documents issued to contractor should include architectural tender drawings that are complete with actual and accurate dimensions. In fairness, Clause 2.6.2 of the BIM Particular Conditions (2nd version) specifies that all dimensions in a model shall be verified on site where possible and applicable before commencing works on site. However, this can be construed as a task to be done on a case by case basis as required and may entitle contractors to additional compensation in case the dimensions provided by the consultants deviated from the site conditions. 

Section 4.7 of the BIM Modelling Guideline is also relevant in this regard. This section essentially provide a workflow of traditional design-bid-build model. Prior to engagement of contractors under pre-tender stage, design and tender documents are only prepared after all conflicts are resolved. Therefore, it raises the question of whether under BIM project, contractors should continue to produce 2D combined services drawings or should such conflict free layout of services be expected in tender drawings issued to contractors. Assuming project engineers and architectural consultants are reluctant to be responsible for the accuracy of the BIM software as it relates to its ability to provide accurate site dimensions and clash free drawings, it begs the question of why should the contractor be expected to rely on the very same BIM software? It should also be noted that under Section 3.4 of Singapore BIM Guide (Version 2), there is an express recognition that with the BIM adoption, design efforts will increase in the upfront phase of the project. Therefore BIM Steering Committee recommends a 5% increase in consultancy fee payment for design development at pre-tender stage that will be cushioned by a corresponding 5% reduction in fee previously allocated for construction administration stage. Therefore, it is reasonable to expect that the level of detail that are typically made available during construction phase can now be included in tender drawings that will be issued to tenderers.

BIM, Security of Payment Act and Claims Management

In Singapore, contractors’ entitlement to progress payments for construction work done is given a statutory force by the Security of Payment (SOP) Act. Any contractor that is financially aggrieved by not receiving progress payment within the prescribed time frame may apply for statutory adjudication under the SOP Act for a speedy and binding resolution of payment dispute. As the adjudication process follows a strict timeline, it is in the contractor’s interest as the claimant to support its adjudication application with incontrovertible evidence demonstrating work done that entitles progress payment. To this end, BIM may provide supplementary digital evidence in support of its payment claim. 

Under a project BIM Execution Plan that is jointly agreed by the Employer and all parties to the project, a digital 3D BIM model provides a baseline plan to measure progress of works throughout the construction period. Various building elements can have its details increased progressively in tandem with the progress of the construction works. There are certain BIM softwares that enable stakeholders across trades to update a central model as work progresses. Some of these progress tracking can be done in real time by having on site camera to support its monitoring function. These digital evidence can be helpful in statutory adjudication since it is in essence evidence from a technology platform that has been jointly agreed by the parties in its adoption and associated factual veracity. Under traditional non BIM payment adjudication application, claimant’s application are usually supported by progress reports, photographic evidence and site diaries. Very often these may be criticised as being self serving paper trails in that these are produced by the very same claimant. Having supplementary BIM digital evidence should address some of these criticism. Apart from having real time tracking of progress of works, it may also facilitate cross comparison against baseline programme to similarly provide an objective measurement of whether works carried out are in tandem with the agreed schedule. In case there are claims for extension of time due to certain events, the details of time impact of such event may also retrieved for further analysis. This in some ways may provide insights on whether any prolongation claims are factually justified.

Conclusion

There are various productivity related benefits associated with the adoption of BIM in construction projects. Contractors that are able to adapt and evolve stand to gain in various aspects of its claims administration and application as well. In the process of embracing BIM, contractors will be well served to be opportunistic on how it could ride the wave of digital disruptions.




Koon Tak Hong Consulting Private Limited