11.3 Reconciling the Cost Approach
Key Takeaways
- Indicated value by the cost approach equals site value plus depreciated cost of improvements (cost new minus accrued depreciation), under a consistent highest and best use and property rights premise.
- The cost approach is generally most reliable for new or nearly new improvements, special-purpose properties, and markets with limited comparable sales; it is least reliable for older properties with heavy, uncertain depreciation or thin/unstable land markets.
- Reconciliation inside the cost approach means checking land, cost new, depreciation method(s), and math consistency—not averaging random land values with unrelated cost bases.
- Final appraisal reconciliation weighs the cost indication against sales comparison and income indications; a weak cost approach may still be reported but should receive less weight when market evidence is superior.
- Common exam errors include depreciating land, omitting entrepreneurial incentive from cost new, double-counting depreciation, inconsistent HBU, and treating cost approach as always equal to market value.
The Last Cost-Approach Step on the ECO
After cost sources, cost components, physical/functional/external depreciation, and depreciation methods, ECO V.g asks you to reconcile to an indicated value by the cost approach. That is both:
- Internal reconciliation — bring land, cost new, and depreciation into one coherent indication.
- Role of that indication — know when it deserves primary weight in the final value opinion (Area VII) versus when it is secondary support.
The Indicated Value Formula
Indicated value by cost approach =
Site (land) value + Cost new of improvements − Accrued depreciation
Equivalently:
Site value + Depreciated cost of improvements
| Component | Must be consistent with |
|---|---|
| Site value | HBU as vacant; same rights and effective date; correct land method |
| Cost new | Reproduction vs replacement as chosen; direct + indirect + entrepreneurial incentive as required |
| Depreciation | Same improvement set as cost new; effective date; no double count |
| Property rights | Fee simple vs other interests; site improvements included/excluded consistently |
Improvements usually include the building and site improvements (flatwork, landscaping, fencing) unless the stem values bare land and structure only. Land is not depreciated.
Worked problem 1 — Complete cost approach
| Component | Amount |
|---|---|
| Land value (sales comparison) | $140,000 |
| Building RCN | $380,000 |
| Site improvements RCN | $35,000 |
| Total cost new | $415,000 |
| Accrued depreciation (all causes) | $95,000 |
| Depreciated improvements | $320,000 |
| Indicated value by cost approach | $460,000 |
Narrative reconciliation note (exam level): Land from three lot sales; RCN from local cost service with entrepreneurial incentive included; depreciation by modified age-life supported by market extraction at ~23%—indication rounded to $460,000.
Worked problem 2 — Build depreciation then reconcile
Land: $200,000
RCN: $800,000 (includes entrepreneurial incentive)
Curable physical: $20,000
Age-life on remainder: EA 10, TEL 50 → 20% × ($800,000 − $20,000) = $156,000
Functional incurable: $40,000
External: $30,000
Total depreciation = $20,000 + $156,000 + $40,000 + $30,000 = $246,000
Depreciated improvements = $800,000 − $246,000 = $554,000
Cost approach indication = $200,000 + $554,000 = $754,000
Worked problem 3 — Two depreciation methods, one indication
Sometimes you compute depreciation two ways and reconcile depreciation before finishing value.
| Method | Depreciation |
|---|---|
| Age-life (EA 25 / TEL 50 on $360,000) | $180,000 |
| Market extraction from comps (~48% of RCN) | $172,800 |
| Breakdown total | $175,000 |
Reconcile depreciation to $175,000 (breakdown detailed; extraction corroborates; age-life slightly high).
Land $90,000 + ($360,000 − $175,000) = $275,000 cost-approach value.
You do not average three different final values built on inconsistent land or cost bases. Reconcile inputs, then compute one indication.
When the Cost Approach Is Most Reliable
| Situation | Why cost approach strengthens |
|---|---|
| New or nearly new improvements | Little accrued depreciation; cost ≈ market for improvements |
| Special-purpose properties (school, church, unique industrial) | Few substitutes; sales comparison thin; cost often primary |
| Limited comparable sales | SCA weak; cost provides independent test |
| Proposed construction / feasibility | Cost is central to residual and go/no-go |
| Insurance / cost-related assignments | Cost new concepts dominate (still know market-value context on National Exam) |
| Consistent HBU as improved matches ideal improvement | Improvements not a major over- or underimprovement |
Exam phrasing: “Most applicable,” “most reliable,” or “given greatest weight” when the property is new special-purpose with few sales—choose cost approach.
When the Cost Approach Is Least Reliable
| Situation | Why cost approach weakens |
|---|---|
| Older improvements | Depreciation large and hard to support; small % errors → large $ errors |
| Heavy functional/external obsolescence | Hard to measure; age-life alone fails |
| Thin or volatile land market | Site value is half the indication; garbage land → garbage total |
| Entrepreneurial incentive unclear | Cost new incomplete or overstated |
| Market values well below replacement cost (declining market) | Cost can overstate market value if depreciation (especially external) is understated |
| Abundant similar sales | SCA more direct; cost may be secondary |
| Income property with strong rent comps | Income approach may dominate for investors |
Exam phrasing: For a 50-year-old house in an active subdivision with many comps, sales comparison usually gets more weight than cost—even if you still develop cost.
Reliability Spectrum (Memory Table)
| Property profile | Cost approach weight (typical) |
|---|---|
| Brand-new tract home; many comps | Useful check; SCA primary |
| Brand-new special-purpose; few comps | Primary |
| 5-year-old house; active market | Supportive |
| 40-year-old house; active market | Lower weight |
| 40-year-old special-purpose; no comps | Still necessary; support depreciation carefully |
| Teardown; land-driven | Cost of building may be near zero contribution; land primary |
Combining Land + Depreciated Improvements — Consistency Rules
- Same effective date for land, cost, and depreciation.
- Same HBU premise — do not add land valued for multifamily redevelopment to a single-family house you assume remains forever without analyzing as-improved HBU (consistent use).
- Site improvements — if included in cost new, do not also bury them entirely in “land” without coordination.
- Rights appraised — leased fee land residual ≠ fee simple land without adjustment.
- Units — whole-property indication; do not mix per-SF building cost with wrong SF (gross living area vs gross building area).
Worked problem 4 — Inconsistent HBU trap
Land as vacant for commercial pad: $500,000.
Existing house RCN $200,000; depreciated contribution $80,000 if continued residential.
Blind sum $580,000 may be wrong if HBU is demolish for commercial: then value ≈ land − demo, and residential building contribution may be $0 or negative net of demo. Cost approach under continue residential is a different premise than redevelop commercial. Reconcile the use first (Chapter 4), then the dollars.
Cost Approach vs Final Reconciliation
| Level | Question |
|---|---|
| V.g Cost approach reconciliation | What single indication does cost support? |
| VII Reconciliation (approaches) | How much weight does that indication get vs SCA and income? |
Example final weighting vignette:
| Approach | Indication | Weight | Comment |
|---|---|---|---|
| Sales comparison | $410,000 | 60% | Four strong comps |
| Cost | $425,000 | 25% | 12-year-old home; dep somewhat uncertain |
| Income (GRM) | $405,000 | 15% | Thin rental set |
| Reconciled value | ≈ $412,000 | 100% | Not a blind mean of unweighted equals |
National Exam items may ask which approach gets most weight—not always the numeric average.
Common Exam Errors (High Yield)
| Error | Correct discipline |
|---|---|
| Depreciating land | Depreciate improvements only |
| Omitting entrepreneurial incentive from cost new when required | Include all cost components in RCN/reproduction |
| Using replacement cost but charging depreciation as if every historic ornament must be reproduced | Match depreciation theory to cost type |
| Double-counting curable items inside age-life and again as line items | Modified age-life / clean breakdown |
| Applying age-life to land + building | Age-life on improvement cost only |
| Ignoring external obsolescence so cost >> market | Include EO or extraction-based total dep |
| Treating cost indication as automatic market value | It is an indication; reconcile |
| Wrong SF basis for cost | GLA vs GBA vs rentable—follow stem |
| Site value from wrong HBU | Land under consistent use |
| Averaging three bad methods equally | Weight by data quality |
Worked problem 5 — Spot the error
Candidate’s work: Land $100,000; RCN $300,000; EA 30; TEL 50; depreciation 30/50 × $400,000 (land+building) = $240,000; value = $100,000 + ($300,000 − $240,000) = $160,000.
Errors: (1) life ratio applied to land+building base; (2) inconsistent bases.
Correct: Dep = 0.60 × $300,000 = $180,000; depreciated improvements $120,000; indication $220,000.
Worked problem 6 — Reliability judgment
Stem: 1970s warehouse, special design, no local sales of similar properties, land sales available, cost manual supportable, depreciation estimated by breakdown with engineering support.
Most reliable approach? Often cost (special-purpose, limited sales).
Alternate stem: 2019 production home, 12 closed sales within 1/2 mile in 6 months—sales comparison most reliable; cost is a check.
Quality Control Checklist Before You “Lock” the Cost Indication
- Land method stated and math checked.
- Cost new: direct, indirect, entrepreneurial incentive (as applicable).
- Reproduction vs replacement identified.
- Depreciation method(s) fit the data (age-life / modified / breakdown / extraction).
- No land depreciation; no double count.
- HBU and rights consistent.
- Final addition: land + depreciated improvements = one indicated value.
- Sensitivity: if EA ±2 years or land ±10% swings value wildly, note lower reliability in reconciliation narrative (exam: expect recognition that old properties are sensitive).
Chapter 11 Synthesis
| Section | Skill |
|---|---|
| 11.1 | EA/TEL age-life; modified age-life with curable first; multiple drills |
| 11.2 | Breakdown by physical/functional/external; market extraction = RCN − (Price − Land) |
| 11.3 | Assemble indication; weight by reliability; avoid classic traps |
Formula card:
- Age-life % = EA / TEL; Dep $ = % × CN
- Modified: Curable + (EA/TEL) × (CN − Curable)
- Extraction: Dep = CN − (Price − Land)
- Cost approach value = Land + CN − Dep
Area V is calculation-heavy at CR and still material at LR/CG. If you can depreciate correctly and know when the resulting indication is trustworthy, you convert cost-approach items into reliable points and support cleaner final reconciliations in Area VII.
Site value is $175,000. Replacement cost new of improvements is $425,000. Accrued depreciation from all causes is $90,000. What is the indicated value by the cost approach?
For which property is the cost approach generally considered most reliable as a primary value indication?