Budget and Contingency Methodology

Primary sources

Renovation cost benchmarks are sourced from RSMeans (a division of Gordian), the construction industry standard for labor and material cost data. RSMeans publishes square-footage costs by project type, region, and construction quality tier (economy, standard, premium). Remodeling Magazine's Cost vs. Value report provides renovation-specific cost estimates (see ROI Methodology).

Contractor markup data is sourced from the National Association of Home Builders (NAHB) Cost of Constructing a Home study and the Remodeling Contractors Association's annual survey. Typical general contractor overhead and profit markup: 20-35% of material + subcontractor costs.

Contingency modeling

Contingency percentage benchmarks by project type: cosmetic remodel (new flooring, paint, fixtures only): 5-10%. Partial gut renovation (kitchen or bath with structural work): 15-20%. Full gut renovation: 20-25%. Major structural work (addition, foundation, load-bearing walls): 25-35%. Historic renovation: 30%+.

These benchmarks reflect the probability and magnitude of scope changes typical at each project complexity level. A kitchen remodel commonly discovers plumbing or electrical code violations when walls open — a 20% contingency covers the modal discovery cost. A simple flooring replacement rarely has surprises.

Labor vs. material split

Average labor/material split by project type (from RSMeans and NAHB data): kitchen remodel: 40% labor / 60% material; bathroom remodel: 50%/50%; flooring: 30%/70%; roofing: 60%/40%; addition: 55%/45%. Geographic labor markets shift the split significantly — high-wage markets (SF, NYC) push labor to 60%+ of total cost.

DIY savings = labor cost × (1 - DIY_skill_factor). DIY_skill_factor ranges from 0 (professional only: electrical, structural, HVAC) to 0.9 (highly DIY-able: tile, painting, simple flooring). We compute max DIY savings but flag permit and liability considerations for trades requiring licensing.

Limitations

Material cost inflation has been volatile since 2020 (lumber, copper, concrete all saw 50-100%+ spikes). RSMeans updates quarterly but published benchmarks may lag spot market prices. Labor costs vary significantly within regions — unionized markets are higher than RTW state markets. Permit costs vary by jurisdiction and are not modeled as a default (1-3% of project cost is a typical range).

Update protocol

This category is reviewed quarterly. Immediate updates are triggered by changes to the primary source documents listed in the citations above — rate table revisions, new agency guidance, or regulatory amendments.

Error reports go to info@bedrockatools.com. Corrections are published on our corrections page.