BIM automates core processes for quantity surveyors in the preconstruction stage by reinforcing the 3D BIM model with material and component cost estimates, model-based BOMs, and scheduling.
The role of a quantity surveyor in the construction industry carries great importance for AEC firms and clients. The quantity surveying practice requires being in charge of calculating building material quantity and finances within required deadlines, which is a crucial responsibility. Taking the role of a cost consultant to generate a Bill of Quantities (BOQ’s) from 2D drawings can be tedious and error-ridden.
Adopting Building Information Modeling (BIM) technology helps quantity surveyors to boost efficiency and business through cost and time savings and improved coordination through accurate information exchange. Adding the most value at the preconstruction stage with parametric modeling enables the quantity surveyors to calculate accurate estimates, automate quantity surveying, speed up costing processes, and precisely capture and use project data.
Challenges faced due to traditional methods of quantity surveying
Traditional quantity surveying has always let down quantity surveyors with challenges that result in project delays due to cost and time overruns. Performing Quantity Takeoff based on 2D drawings for complex construction projects is high-risk.
Quantity surveyors working on fast-paced projects with traditional surveying processes can miss crucial details leading to:
- Uninformed decision-making in the preconstruction stage
- Costly rework due to errors in multiple 2D drawings
- Material waste and costing errors due to missing elements of double counting
- Inaccurate logistics planning
- Errors in data movement within files
- Variations in material quantity and cost during the design phase
- Revision of BOQ’s to accommodate design variations
- Loss of tenders or bids due to inaccurate and incomplete quantity surveying
How BIM affects quantity surveyors
Estimations performed by quantity surveyors have become straightforward with BIM-based cost estimating in comparison to paper drawings.
The potential uses of BIM in modern-day QS practices include:
- Preparation and extraction of accurate Quantity Takeoff’s from 3D models
- Generating precise cost estimates and reports based on components and stakeholder relevancy
- Early clash analysis during the coordination process
- Preparation of BOM’s
- Streamlined bidding and tendering processes based on client compliance and bidding offers
- Financial comparative analysis and value management
- Better sustainability based on formulated financial calculations
- Accurate feasibility studies for greater cost reliability and maximum value
- Promote procurement processes based on informed decisions through digitized building information
- Improved material waste management through model-based simulations
Within the traditional role, the responsibilities of a quantity surveyor were limited to a narrow scope, whereas the modern quantity surveyor needs to do more. From investment appraisals to construction project management, and life cycle costing to value engineering, quantity surveyors need to undertake a broad spectrum work profile, and evolve as professional experts.
Benefits of BIM for quantity surveyors
- Precise model validations to incorporate evolving changes in the design phase
The key competency of BIM for quantity surveyors is the ability to validate model information. Parametric modeling assists quantity surveyors with auto-adjustment of costs based on evolving project data in a Common Data Environment (CDE). Identifying quantities at specific stages or levels through model manipulation helps extract useable measures and quantities.
- Informed decision-making leading to greater productivity and cost savings
Automating core processes enables quantity surveyors to latch on to informed decision-making whilst working on a live model. The productivity factors can be enhanced through 5D BIM, wherein evolving changes can be factored in to keep quantity surveyors updated. This reduces preconstruction communication fragmentation, lowers information conflicts, and mitigates rework leading to project cost savings and reduced project delays.
- Accurate BOQs nullify logistical errors and reduce building material wastage
Accurate and detailed project simulations through 4D BIM can assist quantity surveyors to visualize and plug logistical gaps. As Bill of Quantities is an important tool to generate accurate cost management, BIM provides 5D as a means to automatically produce BOQ’s. BIM can extract quantities and calculate costs at any time during the design stage; and mitigates material waste. Comprehensive knowledge of cost determinants based on the BIM design engine helps churn out accurate and reliable cost estimates.
- Improved bid management with detailed models and drawings
BIM application delivers intensive and detailed deliverables like 3D models and drawings compared to their traditional counterparts. Wrong assumptions based on 2D drawings can lead to bidding losses, whereas the preparation of comprehensive and straightforward construction data diminishes coordination and data gaps amongst various project trades. With the knowledge and skill of extracting accurate quantities from the building model, bidders can put forth winning or competitive bids.
A project management solutions firm from Saudi Arabia needed a coordinated 3D BIM model at LOD 500 for a healthcare facility to achieve better scheduling and ROI. Based on 2D drawings, the project team at Hitech CADD Services generated a clash-free 3D BIM model with accurate material takeoffs.
Onsite risk and rework were mitigated by resolving any trade interferences in the 3D model, and deadlines were met through quick collaboration to streamline tasks, save time, and reduce rework. The 3D model also helped the client achieve higher ROI based on clear and precise scheduling.
Future of quantity surveying with Big Data, AI, and Machine Learning
Enhancing project performance and producing better construction project outcomes through improved overall productivity is key for quantity surveyors. Quantity surveyors have become more mindful of transformational benefits and improvements in quantity measurements through advanced estimating tools. The reinforcement of BIM with Big Data, AI, and Machine Learning will lead to a significant reduction in workloads helping clients to reach maximum value.
Big Data has made QS more realistic through accurate cost data. It integrates a wide range of cost data to generate accurate cost estimates. A series of algorithms, data mining, neural networks, and more are required skills that a modern quantity surveyor needs to acquire.
Artificial Intelligence or AI can process large amounts of historic data and past experiences to prepare an initial cost estimate. Neural networks and regression testing or models help improve the estimation accuracy and enhance the alternative design and material selection.
It has been observed that the accuracy of construction cost at the feasibility stage is within 25% to 30%, and it reduces to less than 20% as the design evolves, and as estimators provide their input. Design decisions can be more realistic, and projects can become more effective, improving the overall construction process.
Machine Learning can help quantity surveyors reduce time and cost overruns for an ongoing project. Extracting potential issues that cause these overruns can help profit maximization for contractors, clients, etc.
The ever-evolving role of a quantity surveyor has led to new services that include value and risk management, FM, sustainability, financing, administration, and more. Furthermore, the maturity of BIM has made it imperative for quantity surveyors to adopt new processes and software-driven technology to generate accurate deliverables at the first instant.
The potential impact of software-driven technologies that are supplemental to BIM will continue to enhance the quantity surveying process. Quantity surveyors will take on a versatile and broad-spectrum profession as they continue to become more effective and productive with BIM.