The advent of 5D revisioning with 3D models is an irreversible industry shift for the quantity surveying profession worldwide.
The ability now exists for the 5DQS to reproduce quantities in a trusted environment, and quickly in comparison to traditional 2D measuring. The technologies and BIM process open up a range of opportunities for the 5DQS to achieve much more for the project team and purposefully contribute to early stages of design. The 5DQS can also provide far greater accuracy of costs and analysis throughout the developed design and construction phases as well as into post construction and facilities management.
The Sunshine Coast University Hospital (SCUH) is the first major new, not replacement, public hospital built in Australia in more than 20 years. It is being delivered as Queensland’s first public hospital Public Private Partnership (PPP), and is due to open in April 2017. The $1.8 billion public tertiary teaching hospital has been built to a 4 star green star rating.
Construction is nearing technical completion and will provide a 450-bed facility over more than 160,000 square metres of hospital space, two multilevel car parks and a range of at-grade spaces providing 3,500 bays across the site. The hospital is expected to grow to its built capacity of 738 beds by 2021.
The Exemplar Health consortium will design, build and partially finance the public hospital as well as maintain it for 25 years.
5DQS model measurement
In early 2013, a team from 5D Quantity Surveyors was engaged to collaborate on the project as a cost planning and procurement team to produce a series of sub-contract guaranteed trade bills of quantities for various trade packages.
The small 5DQS team collocated within the builder’s Brisbane office alongside the cost planning team to not only deliver the packages, but to demonstrate how to interrogate and consume 3D models for the purposes of bill of quantities.
Within just four weeks, a series of trade bill of quantities packages for concrete, formwork and reinforcement for the main hospital building and the hub were successfully delivered, in which multiple revisions of documentation were processed to produce a bill of quantities (BoQ) that was based on the latest information possible.
The dynamic BoQs were based primarily on Revit structural model files. Through validation and transparent communication between the cost planners and designers, full trust in the 3D models was achieved. The team delivered 94 per cent of the items, by dollar value, as 3D items, mapped through the software into the 5D BoQ.
The dynamic links meant the quantities and estimates were able to be quickly calculated and recalculated every time the model information was revised. The team was able to revision within days and sometimes hours to produce updated visualised documentation which clearly identified the changes within the 3D model and include them in the contract.
For the builder, this meant they were able to tender on the latest documents, rapidly updating the final BoQ to the final BIM model, and could communicate these changes quickly to the wider team. For the trade contractors, it meant they could precisely understand the scope of the trade package, eliminate risk from the package and allow for more competitive pricing.
From this success, a new request was made to measure the main hospital building ceilings and partitions and paint packages, amongst others such as floor finishes and various packages for the facilities management building, authored by HDR Rice Daubney in joint venture with Architectus, known as Sunshine Coast Architects (SCA). For these packages the authoring software was Graphisoft’s ArchiCAD, which brought about a new challenge in understanding the models for mapping through quantities.
Through collaboration, coordination and regular communication, the team worked with SCA to overcome specific information problems. The ceilings were not producing information parameters that contained quantity information (such as area, height, and perimeter). It became apparent that only a selection of the depth of information embedded in ArchiCAD objects was available within the exported IFC file. The file was therefore insufficient for transferring into CostX, the 5D authoring tool that facilitates estimating for the total trade package in its default form. The standard settings for the IFC export from ArchiCAD provided partial information but not the detail needed to support a fully measured, accurate estimate that could be revised quickly as the design models developed.
Given that the SCUH was the largest ArchiCAD project underway in Australia at that time, the architects worked with Graphisoft in Hungary to demonstrate the requirements of the software change to better support the collaboration workflow with quantity surveyors. Graphisoft quickly welcomed the opportunity to enhance their product in relation to real project requirements and to expose all of the data regardless of the object being exported. This now means that the interrogation of the data is in the hands of the consultants to utilise at a very detailed level as required by a project. This capability is now part of standard ArchiCAD.
The software change was tested and implemented within two weeks, with quantities produced directly from the model, rather than through a manual step work-around.
For the ceilings and partition packages, every quantity was able to be split by zone (east vs. west), level (00 to 05) and department. The ‘base level’ parameter was readily available from all models, however, zone and department were not. Once again the team worked collaboratively with SCA to understand the information. By holding a number of workshops, a series of workflows were created to obtain a relational link between the spaces within the model to each object in order to define department and therefore zone.
For the complete ceiling and partition, BoQ was then able to be revisioned quickly and the quantities dissected by location into much greater detail, by department or even room by room. This meant increased speed, but also much more flexibility in the way the quantities were presented.
The team produced BoQs and leveraged the software to revision the models on a fortnightly basis. This led to guaranteed subcontract BoQs that were again produced on the very latest information, which reduced the need for addenda.
Furthermore, the bills were produced in a transparent, virtual format of CostX viewer files so that the trade contract tenderers could view each trade package quantity, its location in the model and how the quantity is measured. This technology reduces the reliance on 2D paper drawings and gives subcontractors the opportunity to better understand their tender requirements, easily visualise their components of the project and quickly respond to any revisioning.
By late 2015 when final accounts for subcontract engagement were due, the site team had a strategy for document changes and subsequent variations whereby the final account would be settled at the end of contract and compared against the original guaranteed BoQs. This process meant rather than creating variations as documents changed throughout the construction phase, absorbing time and administrative costs, one effort was made at the end of the project to encompass all changes. For the 5DQS, this is just another form of revisioning – one that was set at the start of the project and therefore not an insurmountable task to complete at the end.
For the first time in Australia on a project of this scale, efficient and effective real-time quantification and costing of revisions and design changes were successfully utilised. This solution has unlocked benefits that due to time, manpower, and cost considerations, have been unattainable to project participants operating in the traditional 2D realm. 3D modelling means 5D real time re-measuring rather than 2D claim, claim, and claim again via the variation process.
As a result of these advances in technology, the quantity surveyor’s role has evolved significantly in the last 10 years. It is now much more about providing design and construction project teams with the power and flexibility of revisioning at multiple times through the process and at any stage.
However, investing in 5D measurement and information at early design stages means the whole project team can be assured of better coordination of documents. This increases the reliability and value of the information and the savings able to be generated. This in turn provides a more informed landscape for decision makers to determine how best to realise these savings throughout the design and construction.
The 5DQS brings technical expertise and market knowledge to the project team and delivers them the understanding of what information and how much of it is useful to create accurate cost plans. It is this intelligence and analysis of model information, identification of clashes in the design phase and the ability to better engage with trade contractors on their packages, that contributes to greater cost certainty across the entire project’s design and construction program.