Change order pricing disputes between GCs and subcontractors on unit-price vs. lump-sum contracts

When a general contractor issues a change order on a project originally bid as lump-sum, subcontractors must reprice new scope without the original competitive bidding leverage, leading to markup disagreements where the GC expects cost-plus-10% and the sub quotes cost-plus-25% to cover remobilization and schedule disruption. This matters because unresolved change order pricing stalls the affected work scope. Stalled work creates cascading schedule delays for downstream trades who cannot begin until the changed work is complete. Those delays trigger liquidated damages clauses against the GC, which the GC then attempts to back-charge to the sub, escalating the dispute into litigation. Litigation costs for mid-size commercial projects average $50K-$150K in legal fees alone, which for a subcontractor operating on 3-5% net margins can be an existential financial event. The sub's bonding company then flags the open litigation, restricting the sub's capacity to bid new work, creating a death spiral where one disputed change order cripples future revenue. This persists structurally because construction contracts lack standardized change order pricing methodologies — the AIA A201 says 'reasonable' markup but never defines it, and every GC-sub relationship negotiates these terms differently, meaning there is no industry-wide default that both parties can point to as fair.