The Three Reasons Construction Projects Actually Overrun
Across the projects we've reviewed or taken over mid-construction, cost and schedule overruns almost never come from unpredictable bad luck. They come from three specific, preventable gaps.
The first is an estimate prepared before design was final. A per-square-foot number quoted at the concept stage, before working drawings exist, is a guess — not a budget. By the time actual quantities are measured against finished drawings, the gap between the early guess and reality has already become a source of client-contractor friction.
The second is uncoordinated vendors. When architecture, structural and MEP consultants work in silos and hand drawings to a contractor sequentially, site-level conflicts — a beam clashing with a duct run, a door swinging into a fixed wardrobe — surface during construction rather than on paper, where fixing them is ten times cheaper.
The third is the absence of a single accountable schedule. When each trade tracks its own timeline independently, delays compound invisibly until a milestone is missed. A master schedule with one owner — whether that's a PMC or a strong general contractor — is what catches slippage while there's still time to recover it.
None of these require exotic solutions. A detailed BOQ prepared from final drawings, design coordination before construction starts, and one master schedule with one accountable owner resolve the majority of overruns we see.
