Change Order Cost Impact Calculator

Revised total = base contract + change orders + contingency. Track scope creep against budget.

Inputs

Result

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How to use this calculator

  • Enter the original signed contract.
  • Sum up all approved change orders.
  • Enter contingency budget set aside upfront.
  • Track cumulative contingency used as work progresses.

About this calculator

Change orders are nearly inevitable on remodels — discovered conditions, scope additions, fixture upgrades. The industry rule of thumb is 3-5% of base for new construction, 8-15% for remodels, 15-25% for older-home restorations. Track each change order separately with: cost, time impact, and signed approval. A "small" change order that adds 5 days × $1,000/day overhead is often the real budget killer, not the visible material cost.

Frequently asked

Should every change be a written change order?+
Yes — verbal "while you're in there" requests cause the most disputes. No work without signed change order.
Why does the GC mark up changes?+
Markup applies to changes too — usually the same 15-25% as the base. Adds cover overhead, supervision, schedule disruption.
My contingency is exhausted — now what?+
Stop and reset. Choose: cut scope (defer items), increase budget, or accept overrun. Don't silently roll into debt.
Is 10% contingency enough?+
New construction: yes. Bath/kitchen remodel: 15%. Whole-house gut: 20-25%.
How do I avoid change orders?+
Spend more on design upfront. Every detail decided pre-contract is a change order avoided. Selections finalized before demo, not during.

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