Civil construction tenders can vary significantly between contractors, even when pricing the same drawings and specifications. In many cases, projects that initially appear profitable can quickly become difficult once construction begins.
Understanding why civil tenders blow out is critical for contractors, developers and project owners looking to reduce risk and improve project outcomes.
Incomplete Scope Information
One of the most common causes of tender overruns is incomplete or unclear documentation.
Missing details around:
– temporary works
– staging
– traffic control
– utility conflicts
– access constraints
– environmental controls
can significantly impact construction costs once works commence.
Many projects are tendered before all site conditions and construction methodologies are fully understood. Contractors are often required to make assumptions during pricing, which can later create variation claims, delays or reduced profitability once construction starts.
Temporary Works Are Often Underestimated
Temporary works are regularly one of the most underestimated components within civil construction tenders.
Items such as:
– temporary access tracks
– dewatering
– crane pads
– sediment controls
– bypass arrangements
– temporary drainage
can create major cost impacts if not properly considered during pricing.
These items are often not measured clearly within the BOQ but still form part of the contractor’s delivery obligation.
Temporary works can also vary significantly depending on weather conditions, staging requirements and site access constraints. Projects near waterways, live traffic environments or existing infrastructure often require additional temporary measures that are difficult to fully quantify during tender.
Production Rates Can Change Quickly
Civil estimating relies heavily on assumed production rates.
Factors such as:
– wet weather
– haul distances
– rock excavation
– restricted access
– groundwater
– subcontractor availability
can significantly reduce productivity on site.
Small reductions in production can have major impacts on labour, plant and programme costs.
For example, a haul route that initially appears achievable may become inefficient once traffic interactions, weather impacts or unsuitable material conditions are encountered. These productivity losses can quickly compound across large earthworks or utility installation projects.
Programme Pressure Impacts Costs
Compressed construction programmes can substantially increase project costs.
Additional crews, overtime, extended supervision and inefficient sequencing can all reduce profitability if not identified during tender.
Projects delivered under grant funding deadlines or public access constraints often carry additional programme risk.
In many cases, contractors are forced to increase labour and plant resources simply to maintain programme requirements. This can create lower overall efficiency and significantly increase operating costs throughout the project duration.
Procurement And Material Risks
Material lead times and procurement risks are becoming increasingly important within civil construction tenders.
Items such as:
– precast structures
– reinforced concrete pipes
– specialised handrail systems
– electrical components
– imported materials
can all impact programme and project costs if not properly considered during tender.
Late procurement or supplier shortages can create delays, increased freight costs and programme disruptions that were not originally allowed for within the tender submission.
Latent Conditions And Site Unknowns
Civil projects regularly encounter latent conditions that are difficult to fully identify during tender.
These may include:
– unsuitable material
– buried infrastructure
– groundwater
– contaminated material
– unexpected rock
– undocumented services
Even with geotechnical reports and survey information, contractors are often required to carry some level of construction risk relating to actual site conditions encountered during works.
This is why experienced
civil estimating and constructability review is critical during
tender preparation.
Why First Principles Estimating Matters
Accurate
first principles estimating requires more than simply applying historic rates.
Detailed
construction-driven estimating allows contractors to properly assess:
– methodology
– plant spreads
– labour requirements
– haul logistics
– temporary works
– programme impacts
This approach helps reduce commercial risk and improves pricing accuracy.
Construction-driven estimating also allows contractors to better understand where key project risks exist before works commence, improving decision making during tender review and project planning.
Conclusion
Many civil construction tender overruns are caused by methodology, programme and temporary works impacts that are not fully identified during tender.
A construction-driven estimating approach helps contractors better understand project risks before works commence and improves the accuracy of tender pricing.
Need support pricing your next civil project?
Geo Civil Estimating provides practical, construction-driven estimating and tender support services across Australia.
