A general contractor’s in-house estimator priced a mid-rise renovation using a Class 3 budget estimate. At that design stage, an accuracy range of about ±20–30% is normal. The client treated the estimate as a fixed number and based the financing on it. When the design reached 60% completion, structural changes increased the cost by 22%. The estimate was still within its expected range, but the client did not understand what “Class 3” meant. This was not a bad estimate. It was a gap that estimating consulting can help prevent.
SMA Estimating LLC’s estimating consulting services help close this gap. The goal is not just to produce numbers. It is to use the right estimate class for each project stage and make sure clients understand how accurate the estimate is.
Why Do In-House Estimates Miss What Estimating Consulting Catches?
Because internal departments often deal with various other projects and do not have enough time to thoroughly research any given hypothesis or evaluate the cost of a solution against outside data. A second review can catch problems that a busy estimator may miss.
Construction estimating consulting can include checking the scope, reviewing quantity takeoffs, and confirming that prices reflect current market conditions. This helps prevent old rates from being carried into new estimates.
How Accurate Should An Estimate Actually Be At Each Stage?
It depends on how much of the design is complete. Pretending that all estimates have the same level of accuracy can lead to budget conflicts. AACE International’s Cost Estimate Classification System (18R-97) sets the industry standard for this.
Estimate Class | Project Definition | Expected Accuracy Range |
Class 5 (Concept) | 0–2% design complete | -50% to +100% |
Class 4 (Feasibility) | 1–15% design complete | -30% to +50% |
Class 3 (Budget Authorization) | 10–40% design complete | -20% to +30% |
Class 2 (Control/Bid-Tender) | 30–70% design complete | -15% to +20% |
Class 1 (Definitive) | 50–100% design complete | -10% to +15% |
Source: (AACE International, Recommended Practice 18R-97)
A Class 5 concept estimate can be 40% off and still be within its expected range. The problem starts when someone treats a Class 5 estimate like a Class 1 commitment.
How Common Are Budget Overruns Across The Industry?
More common than most owners think. This is not a rare problem limited to poorly managed projects. It is common across the industry.
According to KPMG's Global Construction Survey 2025/2026, only 25% of construction projects are completed within 10% of their initial budget. This means that 75% of construction projects are completed beyond their initial budget target. One reason can be using an estimate class that does not match the decision being made.
Where Does Consulting Add The Most Value In Project Planning?
At the transition points, when a project moves from concept to budget approval or from budget to bid-ready pricing. This is where the estimate should become more detailed. It is also where mistakes can slip through.
Project cost estimation reviewed at each stage can catch scope gaps in key CSI divisions. This includes Division 03 (Concrete), Division 23 (HVAC), and Division 26 (Electrical). Finding these gaps early can help prevent change orders during construction.
What Does Good Project Planning Actually Require?
The estimate should match the decision being made. Financing, bidding, and construction project planning all need different levels of accuracy. Treating every estimate the same can lead to problems.
SMA Estimating LLC works with project teams at each stage. They review assumptions, check quantities against current material and labor costs, and flag when the estimate class does not match how the estimate is being used.
Conclusion
Estimating consulting is not about replacing an in-house team. It is about finding the gap between what an estimate can support and how people use it to make decisions. With only one in four projects finishing within 10% of the original budget, that gap can cost real money. SMA Estimating LLC helps close this gap by matching the estimate class to the project stage. This helps teams build budgets on the right level of detail instead of treating an early estimate as more certain than it really is.
