As one of the world’s largest current infrastructure projects valued at approximately £15 billion, Crossrail in London encompassed 25 design contracts, 30 main works contracts, 60 logistics main works contracts and the creation and management of over one million digital files (drawings and models).The sheer scale and complexity of this project has proved an ideal environment in which to maximise the benefits of implementing Building Information Modelling (BIM). It has led to a reduction in design and construction risks, errors and omissions, better safety outcomes, greater collaboration, reduced information loss and improved project delivery.
While most projects cannot easily compare to Crossrail, the value of BIM is equally applicable to the construction sector in New Zealand.
As a member of the NZ BIM Acceleration Committee, Glenn Jowett, Technical Director for Digital Engineering Advisory, explores local and international case studies to share some insights into the value of BIM, a decade after the May 2011 UK Government Construction Strategy, which recommended an industry-wide BIM mandate, and approximately eight years since the NZ BIM Acceleration Committee was formed.
The use of BIM reduces design risk through several factors including visualisation, collaboration and communication. The capacity for visualisation using BIM can offer stakeholders a virtual view of a completed asset. This significantly improves stakeholder engagement, understanding and agreement on the proposed solution, and minimises the likelihood of design changes later in the process.
Reduced design risk
For example, BIM was used on the Christchurch Justice and Emergency Services Precinct as a stakeholder engagement tool with judges and tenants. What is typically a very time-consuming process was made much smoother through three-dimensional walk-throughs and visualisations.
Visualisation and collaborative workflows also ensure a consistent view of the design intent across the design team. Coordinated spatial modelling helps to reduce errors in design and cost modelling in BIM (5D BIM) in the early project stages, which improves design cost certainty through faster, more accurate cost reporting. For example, by sharing design elements while maintaining one version of the ‘truth’ on the University of Auckland Engineering School, we effectively de-risked a highly complex design phase.
Reduced construction riskBIM can reduce construction tender risk, minimise unforeseen issues during construction and support the development of project specific construction methodologies, optimising sequencing and build confidence in the programme. In the design stage, the coordinated approach supported by BIM ensures early identification and mitigation of issues to reduce unknowns in construction, as well as minimise RFI’s and variations and associated re-work.
The provision of a 3D model at tender stage allows the contractor to better understand the design intent and to interrogate the design for pricing and construction methodology. The use of construction sequencing (4D BIM) can further improve construction methodology and logistics planning. 4D BIM also supports clear communications on methodology and helps to avoid misinterpretations.
Reduced construction timeThe gains made by reducing risk in both design and construction through BIM has the inevitable potential for time saved in construction.
The Ara Institute ‘Kahukura’ block is one of the greenest buildings in the Canterbury reconstruction programme. Using BIM throughout the design stages of this complex project enabled production of the developed design cost plan in 20 hours instead of the usual one to two weeks required for a traditional, non-digital process. Ara understood the value of using BIM and saw that it enabled a process to achieve excellence from their consultant team. Importantly, the client endorsed this sharing of information, recognising that collaboration was essential to successful delivery. 
Other examples include the University of Auckland Undergraduate Laboratories, where BIM allowed the estimators, contractors and subcontractors to visualise and co-ordinate a fully integrated system before and during installation. This resulted in reduced material and labour waste, and a shorter construction time, saving almost two weeks in a very tight programme. 
Improved safety in design outcomesThe collaborative workflows and visual communication enabled by BIM contribute to better safety outcomes. Spatial coordination and planning in the pre-construction phases ensure aspects such as safe working zones, maintenance access, and escape routes are factored into the design.
Other safety benefits include:
- The use of virtual reality can also improve the effectiveness of site and safety inductions.
- Construction sequencing in BIM and the ability for scenario planning can contribute to hazard and accident prevention.
- BIM also supports model-driven pre-fabrication and off-site fabrication contributing to safer construction sites
Improved asset management outcomesBIM processes can support the capture of asset data to the required level of detail, either during the construction process or retrospectively.
Asset data captured and linked to a 3D model and database enables optimised data transfer into Asset Information Management Systems. Verified, relevant and integrated asset information – a centralised source of truth – in turn supports fast access to the right information, improved asset understanding and better decision making and forecasting.
An example of how BIM outputs were used to populate asset and facilities management systems was the Bracken Rd Flats revamp project, where there was little or no data available for an asset. Wellington City Council’s day-to-day maintenance activity improved as building managers worked with a more detailed picture that showed the location and status of building components, such as plumbing and HVAC systems. Tradespeople also benefitted, as they had clearer instructions about what to look for and where to find it when attending a job.
Improved cost savingsCost savings associated with BIM implementation generally centre on the following key areas:
Capital cost savings are achieved through better awareness of the physical configuration of the asset. Projects generally require less time on asset records and information research. Proposals from contractors are better defined resulting in more narrow cost spreads due to fewer unknowns, and main contractor variations are reduced due to a better shared understanding of design intent and delivery.
Operational cost savings are achieved by managing data from a centralised source of truth. Asset information is captured in a single place and is updated for all systems that need it at any one time. For example, aerial photography can be maintained in a single location but accessible via multiple sources. Efficiency of operations and of staff are realised by eliminating duplication of data, while at the same time increasing the quality and confidence of data. Examples of improved operational cost savings include:
- By applying BIM, the 39 Victoria Street refurbishment led to savings (including operational estimates) of £676,907, which equates to a 3% saving on whole of life costs over a 13-year period.
- The Foss Barrier Upgrade project, where the application of BIM led to savings (including operational estimates) of £367,693, which equates to a 1.5% saving on whole of life costs over a 25-year period.
Intangible operational cost savings are also important, but harder to quantify. For example, what cost savings can be attributed to emergency responders being better able to respond to an emergency using real-time data on mobile tablets, which results in a more targeted and successful response without loss of life or damage to assets? Optimisation of workspaces may lead to more productive outcomes on manufactured goods that are also difficult to quantify in terms of savings.
Intangible capital cost savings are also difficult to quantify. For example, how to calculate the cost savings achieved from a fully integrated design and improved understanding of the construction sequence, which results in a reduction in RFIs during construction and a shorter construction programme?
Rework – There are many causes to rework, with estimates as high as 20% of capital costs. Even if this figure was 5%, it still translates to significant potential savings from capital expenditure budgets alone. Avoidance of problems during construction associated with errors and omissions, time delays and quality issues is a direct financial benefit. Who stands to recoup this benefit may depend on the contractual agreement and procurement model used. The varying causes of rework in construction have been well documented.
Variations – A study in the United States by mechanical construction firm J.C. Cannistraro of 408 projects valued at $559m in total, shows how BIM saved money as the team became more collaborative. Two-dimensional project collaboration resulted in an additional 18.5% capital spend due to variations. Collaborative BIM reduced these variations down to 2.7% additional capital spend.
Is BIM right for your project? – the BIM Value Framework
The value of BIM adoption is widely documented, but not always understood and rarely benchmarked or measured. To help understand if construction projects in New Zealand could benefit from the use of BIM, we have created a framework that highlights the potential tangible and intangible benefits of BIM, supported by examples. The framework shows how they relate to time, cost and quality, and at which stage of the project and asset lifecycle they might be achieved. These are described in detail in the following download here.
BIM may still be maturing in the construction sector in New Zealand. However, the opportunities for reduced whole of life costs, improved safety, better collaboration and reduced risks in design and construction, are backed up by success stories from many international and a growing number of local projects as described in this article. Beca has strong expertise and experience in BIM implementation on a range of projects. For more information about how we can unlock the value of BIM for you, please get in touch.
 BIM. (2019, April 5). Christchurch Justice & Emergency Services Precinct. https://www.biminnz.co.nz/casestudies/2019/4/9/christchurch-justice-amp-emergency-services-precinct
 BIM. (2019, April 17). University of Auckland Engineering School https://www.biminnz.co.nz/casestudies/2018/university-of-auckland-engineering-school
 BIM. (2019, April 9). Ara Institute of Canterbury Kahukura Block. https://www.biminnz.co.nz/casestudies/2017/ara-institute-of-canterbury-kahukura-block
 BIM. (2019, April 3). University of Auckland Undergraduate Laboratories. https://www.biminnz.co.nz/casestudies/2019/4/9/university-of-auckland-undergraduate-laboratories
 BIM. (2019, April, 23). Bracken Rd Flats Revisit. https://www.biminnz.co.nz/casestudies/2019/bracken-rd-flats-revisit
 www.pwc.co.uk. (2018, March). BIM Level 2 Benefits Measurement. Application of PwC’s BIM Level 2 Benefits Measurement Methodology to Public Sector Capital Assets. https://www.cdbb.cam.ac.uk/files/4.pwcbmmapplicationreport_0.pdf
 See above.
 Cannistraro, M. P. (April, Fall). Savings Through Collaboration: A Case Study on the Value of BIM. https://www.brikbase.org/sites/default/files/Pages%20from%20jbim_fall10-6.cannistraro.pdf