Construction Margin Leak Calculator

How much are preventable issues costing your business? Every project has issues. The question is how much those issues are costing you before they're identified, corrected, or passed along.

Residential Builder

Custom homes, production homes, remodels, and additions

Default change order impact $4,000

Commercial Builder

Commercial, multifamily, industrial, healthcare, and tenant improvement

Default change order impact $8,000

Builds both residential and commercial? Run the calculator that represents your primary business. We can run the other one in a follow-up conversation.

A diagnostic tool by Walk Your Plans Des Moines. Default assumptions are working estimates based on industry benchmarks and can be adjusted to reflect your actual experience. See full sources below.

Sources & Methodology

Change Order Cost Benchmarks

  • CoConstruct (2021): Small construction projects with 3+ change orders averaged $3,854 per change order; with a single change order, $4,639. Home building projects averaged $7,479-$11,180 per change order. View source
  • Rhumbix: Change orders account for 10-15% of total contract value on major projects; some projects see 25%+. View source
  • SpecFinder: Cumulative change orders run 8-14% of original contract value; distressed projects can reach 25%. View source
  • Helonic (2026): Commercial projects typically see 5-10% of contract value in change orders. View source

The $4,000 (residential) and $8,000 (commercial) defaults fall within the range of these industry data points. They are working assumptions, not national averages. Adjust them to match your actual experience.

RFI Processing Cost

  • Navigant Construction Forum (2013): Study of 1,362 projects and 1+ million RFIs found an average of $1,080 to review and respond to each RFI (8 hours of combined labor). Average project: 796 RFIs, $859,680 total. Procore | ASCC | Construction Dive
  • Updated estimates (2024-2026): When rework, schedule delays, and field coordination are included, the real cost per RFI is estimated at $2,000-$3,000.

Rework & Field Cost Benchmarks

  • ASCE Journal of Construction Engineering & Management: Peer-reviewed study found field rework costs average 0.38% of contract value pre-completion, approximately 0.76% including post-completion corrections. Via Level CFO
  • Construction Industry Institute (CII): Older estimates place field rework above 5% of contract value.

Cost Index Methodology

There is no daily or monthly "change order ticket index." The industry-standard method for updating flat dollar figures over time is to adjust baselines using a Construction Cost Index (CCI). Recommended indices:

  • ENR Construction Cost Index: Tracks cement, lumber, steel, and labor across 20 U.S. cities. Current annual escalation: ~3.1% (Aug 2026). ENR Economics
  • Mortenson Construction Cost Index: Updated quarterly; maps non-residential building costs by market.
  • Turner Construction Index: Measures non-residential construction costs including labor, material, and contractor margins.
  • U.S. Census Bureau Construction Price Indexes: Monthly federal updates on single-family home construction cost inflation.

This calculator does not assume every issue is preventable. It puts a dollar value on the uncertainty already present in your construction process. All default assumptions are editable working estimates. Walk Your Plans Des Moines does not guarantee specific cost savings.