7.4 Influences on Land or Site Valuation
Key Takeaways
- Plottage is the increment in value created by combining parcels (assemblage) so the whole is worth more than the sum of separate values; assemblage is the process of combining.
- Excess land can be sold off or used independently; surplus land is not needed for the existing use but cannot be separated—valuation treatment differs.
- Topography, access, utilities, zoning, easements, and view change buildable area, cost, marketability, and unit prices in land sales comparison.
- Environmental stigma and contamination can reduce land value through cost to cure, use limitations, market resistance, and longer marketing times—even after physical cleanup.
- Influences must be reflected in comparable selection and adjustments; describing a factor without pricing it (when material) weakens the land value opinion.
Influences Complete the Land Valuation Story
Methodology (sales comparison, allocation, extraction, residual, subdivision, ground rent) answers how to estimate land value. ECO III.b Influences on land or site valuation answers what moves that value between otherwise similar parcels. On the National Exam, influence items often appear as definition matching (excess vs surplus; plottage vs assemblage) or as vignettes where the correct adjustment or HBU hinge is a site factor—not a cap rate.
Influences overlap property description (Area II) and forces on value, but here the focus is: how each factor changes land price, unit of comparison, or method choice.
Plottage and Assemblage
| Term | Meaning |
|---|---|
| Assemblage | The process of combining two or more parcels into one ownership/tract |
| Plottage (plottage value) | The increment in value created by combining parcels so that the utility/value of the whole exceeds the sum of the separate parcels’ values |
Example: Three adjoining 5,000 SF lots are each worth $100,000 as separate single-family sites (sum $300,000). Combined, they support a 12-unit project and the assembled site is worth $450,000.
Plottage value = $450,000 − $300,000 = $150,000.
Appraisal implications
- A sale to an assemblage buyer may include a premium not applicable to a one-off buyer of a single lot—adjust conditions of sale or reject as a pure comp for non-assemblage subjects.
- HBU as vacant may be a larger combined use even when each lot’s stand-alone HBU is single-family—if combination is reasonably probable.
- Cost of assemblage includes purchase prices, time, risk of holdouts, and demo—plottage is not automatic.
Exam trap: Calling every merger “plottage.” If combined value equals the sum of parts, assemblage occurred but plottage value is zero.
Excess Land vs Surplus Land
Both mean “more land than the current improved use needs,” but marketability of the extra land differs.
| Excess land | Surplus land | |
|---|---|---|
| Needed for current improvements? | No | No |
| Can it be sold off or used independently under HBU? | Yes (legal and physical separability / independent utility) | No (cannot be separated or has no independent HBU/market) |
| Valuation treatment | Often valued as a separate parcel (or distinct land component) under its own HBU | Value may be limited; contributes little or is tied to the main site’s use (possible expansion utility) |
| Example | Extra acre behind a store with road frontage and zoning for a second pad that can be split | Extra backyard depth on a residential lot that cannot be subdivided under zoning and has no separate access |
Worked recognition example
Subject: Retail building on 3.0 acres. Building, parking, and circulation need 1.2 acres. Rear 1.8 acres has dedicated street access, utilities, and zoning for a second commercial pad; similar pads sell for $12/SF.
- Extra 1.8 acres is excess land → value main site for the retail use plus excess land at commercial pad unit values (less split costs if any).
Alternate facts: Extra land is a 40-foot unbuildable strip inside setbacks with no access and no subdivision potential → surplus land; do not assign full pad unit value.
Exam tip: “Extra land” in a stem is incomplete—ask can it be sold or used separately? Yes → excess; no → surplus.
Topography
Topography (slope, elevation, rock, drainage pattern) affects:
- Buildable area and foundation cost
- Drainage and retaining walls
- ADA/access grades
- View potential (positive) vs slide/flood risk (negative)
- Subdivision lot yield (steep land may yield fewer lots)
| Condition | Typical land-value effect |
|---|---|
| Level, well-drained pad | Baseline / preferred for many commercial and production residential uses |
| Moderate slope with view | May be premium for residential; cost add for commercial pads |
| Steep hillside | Lower unit value or higher $/buildable SF after reduced yield |
| Bowl / poor drainage | Discount for cost to cure or stigma |
| Rock requiring blasting | Discount equal to incremental development cost (market-supported) |
Sales comparison: Prefer comps with similar topography or adjust using cost to cure / paired sales—not a fixed national percentage.
Access
Access is both legal and physical:
- Public road frontage vs private easement vs landlocked risk
- Curb-cut permits, median cuts, traffic signal proximity
- Truck routing for industrial; customer convenience for retail
- Corner influence (often positive for commercial; mixed for residential)
Landlocked or easement-only parcels often sell at steep discounts until legal access is cured. A site with two arterial frontages may command a corner premium in retail land pricing ($/FF or $/SF).
Worked sketch: Interior commercial acre sales at $15/SF; true corner with signalized access at $22/SF in same corridor. Subject is corner with similar signal → weight corner comps; do not average in mid-block sales without large adjustments.
Utilities
Utility availability, capacity, and distance change site readiness and value:
- Public water/sewer vs well/septic suitability
- Electric three-phase capacity for industrial
- Stormwater infrastructure requirements
- Impact fees and connection charges (who pays)
A “cheap” raw parcel without sewer in a jurisdiction that requires public sewer for subdivision may be worth far less than unit prices of utility-served sites imply. Adjust land comps for cost to extend utilities and for time/risk if extension is uncertain.
| Utility status | Land valuation note |
|---|---|
| At site / at curb | Finished-site competitive set |
| At street but not lateral | Minor connection cost adjustment |
| Distant extension required | Major adjustment or different product class |
| Moratorium / no capacity | May kill density HBU; value drops to allowed lower use |
Zoning and Land-Use Controls
Zoning sets legal allowability for HBU and caps density (units/acre, FAR, height, lot coverage). Related influences:
- Overlays (historic, flood, design review)
- Setbacks and parking ratios reducing effective buildable area
- Probability of rezoning (must be market-supported)
- Nonconforming rights on improved property (more HBU-as-improved than vacant land, but affects teardown land math)
Two parcels, same acreage:
- Zoned 4 units/acre vs 20 units/acre in a strong multifamily market → radically different land value even if physical sites match.
Unit of comparison may shift to $/buildable unit or $/FAR SF so density differences are explicit.
Easements and Encumbrances
Easements can reduce buildable area, limit use, or (rarely) add value (shared access that cures landlock).
| Easement type | Common effect on land value |
|---|---|
| Utility easement along rear 10 feet | Often modest if outside buildable envelope |
| Cross-parcel access easement through center | Can destroy pad efficiency; large discount |
| Conservation easement | May extinguish development rights; value approaches restricted-use land |
| Aerial / view easement | Case-specific |
| Encroachment / unclear title | Marketability discount until cured |
Always coordinate with the rights appraised. Land sales comparison should match encumbrance status or adjust.
View and Amenities
View (water, skyline, golf, mountains) is a classic residential and hospitality land premium. Measure by paired land sales when possible: similar lots with/without view. Avoid double-counting view in both location and view line items.
Negative “views” or adjacencies: power lines, industrial outlook, billboard backs—treat as external influences on land, not only on buildings.
Environmental Stigma and Contamination
Environmental conditions affect land through:
- Cost to cure (remediation, demolition of contaminated soil, monitoring)
- Use limitations after cleanup (restricted residential use, caps, institutional controls)
- Stigma — residual market resistance even when engineering risk is mitigated
- Time — longer marketing, fewer lenders, fewer buyers
| Situation | Valuation tendency |
|---|---|
| Clean Phase I, no issues | Baseline |
| Known contamination; cure cost $200,000; after cure use unrestricted | Land value ≈ clean value − cure − stigma/time adjustments |
| Cleaned site with deed restriction barring residential | Value on restricted HBU only |
| Neighboring Superfund publicity, subject clean | Possible stigma discount if market shows resistance |
Exam nuance: Stigma is a market phenomenon, not only a lab result. Support with sales, broker evidence, or longer DOM—not pure opinion. Extraordinary assumptions or hypothetical conditions about environmental status must follow USPAP rules (tested more in USPAP chapters) but land value still depends on the assumed condition.
Bringing Influences into the Land Grid
Subject: 12,000 SF commercial site; level; full utilities; light utility easement on rear; good arterial access; zoning C-2; no view issue; clean environmental.
Comp issues to adjust:
| Comp | Influence difference | Directional adjustment to comp price |
|---|---|---|
| Steep site | Topography inferior to subject | + to comp (subject better) |
| No sewer | Utilities inferior | + to comp |
| Corner with signal | Access superior | − to comp |
| Assemblage premium sale | Conditions of sale | − premium if not applicable to subject |
| Partial contamination uncured | Environmental | Treat carefully; may reject |
Remember adjustment direction: adjust the comparable to the subject. If comp is inferior, adjust comp upward.
Link to Methods
| Influence | Method impact |
|---|---|
| Plottage | May justify subdivision residual or higher density residual vs stand-alone sales |
| Excess land | Split valuation; do not bury excess in a single average $/SF from undersized comps |
| Zoning density | Prefer $/unit or $/FAR; residual/subdivision inputs change |
| Utilities/topography | Development cost lines in subdivision analysis; readiness adjustments in sales comparison |
| Ground lease + stigma | Cap rate or rent may embed risk; disclose |
| Easements | Buildable SF in unit comparison shrinks |
Worked Integrated Example
Parcel A: 2.0 acres, level, utilities, zoned 8 units/acre MF, clean, public road → supportable land value from MF lot comps $1,200,000 ($150,000/acre or $75,000 per potential unit × 16 units, depending on unit used).
Parcel B: Same size and zoning map label, but 30% of area is steep unbuildable slope, sewer 1,000 feet away (extension cost $180,000), and a 40-foot drainage easement removes two potential units. Market still wants MF.
Analysis:
- Effective yield maybe 10–11 units not 16
- Subtract PV of utility extension and extra foundation costs from residual or adjust comps
- Indicated value materially below $1,200,000—perhaps mid–high six figures depending on numbers
Same “2 acres MF zoning” headline; different influences; different land value. That is the ECO III.b point.
Common Exam Traps
- Swapping definitions of excess and surplus land
- Confusing assemblage (process) with plottage (value increment)
- Assuming more acreage always means proportionally more value (ignores surplus/excess and diminishing returns on depth)
- Ignoring easements when calculating buildable area for $/SF
- Treating environmental stigma as zero because a report says “closed in place” without checking market behavior
- Applying residential view premiums to industrial land (wrong market)
Chapter 7 Synthesis
| Section | You should now be able to |
|---|---|
| 7.1 | Grid land sales with correct units; separate raw vs finished |
| 7.2 | Allocate by L/V ratio; extract land = price − depreciated improvements |
| 7.3 | Land residual; subdivision PV logic; ground rent V = I/R |
| 7.4 | Name and apply plottage, excess/surplus, physical/legal/environmental influences |
Area III is a modest percentage of the exam, but it is high leverage: site value feeds cost approach, HBU, and redevelopment logic across the rest of the test. If you can pick the right method for the data given and adjust for the influences that make one site unlike another, you will bank these items efficiently and support cleaner answers in Areas IV–VI.
Two adjoining lots each worth $80,000 separately are purchased and combined. The assembled parcel is worth $200,000 because it can support a higher-intensity use. Which statement is correct?
A retail site includes more land than the store and required parking need. The extra land has its own road frontage and can be legally subdivided and sold as a second pad. This extra land is best classified as: