Renovation contingency estimator

Renovations go over budget for predictable reasons: hidden conditions, scope creep, substitutions, and change orders. This estimator helps you plan a realistic total.

Educational tool This is planning math, not a quote. Permits, structural issues, and regional labor/material costs vary widely. Always verify with qualified professionals.

1) Base budget

Base quote

The main contractor quote (example: 25000)

Contingency %

Common: 10–20%

Permits / fees

If unknown, use a buffer

Design / drawings

Optional but common

Schedule buffer

Storage / extra rent / carrying costs

Materials upgrades

Selections above allowance

Calculate

Updates totals + log

Reset

Back to defaults

2) Change-order log

This simple log helps you avoid “death by a thousand small additions.” Enter up to 6 change orders (you can expand later).

Change order	Cost

3) Results

Item	Amount
Total projected renovation cost	$0

Contingency is not “extra money to spend.” It’s a risk buffer for hidden conditions and unavoidable changes.

Reduce overruns Write the scope clearly, confirm what’s included/excluded, and require written approval for every change order. See Renovation overruns explained.

Common overrun triggers (quick checklist)

Hidden conditions (water damage, wiring, framing, asbestos, rot)
Scope creep (one more thing… repeated)
Materials substitutions and lead times
Permits/inspections not planned
Unclear allowances (cabinets, fixtures, tile, flooring)

Author: Daniel Westmere

Daniel Westmere writes about residential property ownership costs, budgeting considerations, and financial risks associated with buying, owning, and selling property.