Key Takeaways
- Start exterior—often the highest-cost elements.
- Interior follows system hierarchy: MEP then finishes.
- Reference table of 20-30 items enables rapid estimation.
- Add GC overhead, contingency, and soft costs to subtotal.
The step-by-step walkthrough estimation process with mental math shortcuts.
Exterior Estimating
Roof (squares × $400-$700), windows (count × $400-$800), foundation ($5K-$15K if cracked), siding (area × $3-$15/SF).
Interior Estimating
Panel ($2K-$4.5K), HVAC ($5K-$12K), kitchen minor ($15K-$30K), bathroom ($12K-$25K each), flooring ($3-$15/SF), paint ($2-$4.50/SF).
| Item | Method | Range |
|---|---|---|
| Roof | Squares × $400-$700 | $8K-$25K |
| HVAC | Tons × $2.5K-$4.5K | $5K-$12K |
| Kitchen minor | LF × $200-$300 | $15K-$30K |
| Bathroom mid | Each | $12K-$25K |
| Flooring LVP | SF × $5-$10 | $4K-$15K |
Quick estimation reference
Assembling the Estimate
Sum line items + General Conditions (5-8%) + Contingency (10-20%) + Soft Costs (3-8%) = Total Renovation Budget.
Guided Practice: Walkthrough Estimate: 1,800 SF Colonial
Touring a 1975 colonial listed at $180K with $290K ARV.
- 1Exterior: roof $11K, windows $8.4K.
- 2MEP: panel $3.5K, HVAC $9K, water heater $1.8K.
- 3Kitchen $21.2K, baths (2) $36K.
- 4Flooring $9.8K, paint $5.4K, trim $3.5K.
- 5Total with markups: $138,623.
- 670% Rule: $203K - $138.6K = $64.4K max offer. Pass.
Key Takeaways
- ✓Start exterior—often the highest-cost elements.
- ✓Interior follows system hierarchy: MEP then finishes.
- ✓Reference table of 20-30 items enables rapid estimation.
- ✓Add GC overhead, contingency, and soft costs to subtotal.
Sources
- RSMeans/Gordian Residential Cost Data(2025-01-15)
- NAHB Construction Cost Survey(2025-01-15)
Common Mistakes to Avoid
Focusing interior estimate on finishes while neglecting MEP assessment
Consequence: Missing a $9,000 HVAC replacement or $3,500 panel upgrade that dramatically changes the budget
Correction: Follow system hierarchy during walkthrough: MEP systems first, then finishes
Not applying the 70% Rule as a screening check
Consequence: Proceeding with detailed analysis on properties that fail basic profitability screening
Correction: Calculate max offer using 70% Rule before investing time in detailed estimation
Test Your Knowledge
1.Where should walkthrough estimating begin?
2.What is the correct order of cost additions to arrive at total renovation budget?
3.In the case study, what was the correct acquisition decision?