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)