What is the primary cause of variance in bids?

• A. Lack of market data
• B. Weather variability
• C. Inability to estimate costs accurately often caused by lack of accurate cost records
• D. Poor supplier relationships

Answer: (C)

Bid variance mainly comes from how accurately costs are estimated. When there are no reliable cost records, estimators must rely on assumptions for labor, material, equipment, and overhead, plus contingencies. Those assumptions vary from one estimator to another, producing different bid totals. If cost data were solid and standardized estimating methods used, bids would cluster more tightly. External factors like market data gaps, weather, or supplier price changes can influence costs, but they affect the estimates or actual costs rather than being the root cause of the bid spread; the core issue is the quality of cost data and the estimation process itself.