GWhy Estimates Get Sent Back at Technical Sanction
Most estimates are not rejected for being wrong — they are returned for being unverifiable. The difference is in the supporting detail.
Unverifiable rates
The commonest reason an estimate comes back is that a rate cannot be reconstructed. If the lead for sand, the lift for deep excavation or the cost index applied is not shown, the sanctioning authority cannot check the figure and will not pass it. Every rate that departs from the bare Schedule of Rates needs its workings attached.
Hiding leads, lifts and contingencies inside a lump item rate feels tidy but is exactly what triggers a query. Carry them as separate, visible heads.
Quantities without a basis
The second recurring reason is quantities that have no backing. An earthwork quantity with no cross-section levels, a pipe length that does not match the line diagram, or a masonry volume that cannot be traced to a drawing invites doubt. Tie every quantity to a drawing, a measurement or a clear computation.
An estimate that reads as a self-checking document — each rate reconstructable, each quantity traceable — clears technical sanction in one pass far more often than one that relies on the preparer being available to explain it.
Why are estimates rejected at technical sanction?
Most often because a rate cannot be reconstructed (missing leads, lifts or cost index) or a quantity has no backing drawing or computation — making the estimate unverifiable rather than wrong.
How should leads and lifts be shown?
As separate, visible heads with their computed distances, not hidden inside a lump item rate, so the sanctioning authority can check each one.
How do I make quantities verifiable?
Tie every quantity to a drawing, a measurement or a clear computation — for example earthwork to cross-section levels and pipe lengths to the line diagram.