# Severance Damages Quantification

> Use when valuing the remainder after a partial taking — quantifying frontage loss by road class ($/linear foot), circuitous-access capitalization, landlocked-parcel easement cost-to-cure, shape-efficiency-driven development yield loss, or farm operation disruption (fencing, equipment crossings, irrigation severance). Before/after method with cost-to-cure vs. value-loss reconciliation.

- Skill: `reggiechan74/severance-damages-quantification` (Agent Skill, multi-file: 35 files)
- Install (CLI): `npx skillmds@latest add reggiechan74/severance-damages-quantification`
- Raw SKILL.md: https://api.skillmd.com/api/skills/reggiechan74/severance-damages-quantification/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: reggiechan74 (https://skillmd.com/u/reggiechan74)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/reggiechan74/severance-damages-quantification

---


**Scope boundary**: This skill covers *structural/configurational* loss to the remainder after a partial taking (frontage, shape, access, utilities, farm severance). For *external* impacts from the works (noise, dust, vibration, proximity, business loss during construction), use `injurious-affection-assessment`. Both fall under OEA s.18.

## Access Impairment Analysis

Quantifying reduced access value from loss of frontage, circuitous access, or landlocked conditions.

### Direct Frontage Loss ($/Linear Foot by Road Classification)

**Methodology**: Value contribution of road frontage analyzed by linear foot based on road classification and development potential.

**Highway frontage (400-series, divided highway)**:
- **Commercial development potential**: $500-$1,500/linear foot
- **Industrial development potential**: $300-$800/linear foot
- **Residential development potential**: $150-$400/linear foot

**Arterial road (4+ lanes, signalized intersections)**:
- **Commercial**: $300-$800/linear foot
- **Industrial**: $200-$500/linear foot
- **Residential**: $100-$250/linear foot

**Collector road (2-4 lanes, local significance)**:
- **Commercial**: $150-$400/linear foot
- **Industrial**: $100-$300/linear foot
- **Residential**: $50-$150/linear foot

**Local road (2 lanes, residential access)**:
- **Residential**: $25-$75/linear foot
- **Agricultural**: $10-$30/linear foot

**Example calculation**:
- **Before**: 200 acres with 800 linear feet of highway frontage, valued at $40,000/acre = $8,000,000 total
- **After taking**: Highway widening takes 50-foot strip along entire frontage, removing all direct highway access
- **Frontage value component**: 800 LF × $600/LF (industrial development) = $480,000
- **Remainder value**: $8,000,000 - $480,000 (frontage premium) = $7,520,000 baseline + frontage loss
- **Severance damage**: **$480,000** for loss of direct highway access

### Circuitous Access (Time-Distance Modeling, Traffic Counts)

**Methodology**: Quantify value loss from increased travel time/distance to reach remainder parcel after taking eliminates direct access.

**Time-distance modeling**:
- Measure travel time before and after taking
- Apply value-of-time metric (typically $25-$50/hour for commercial/industrial users)
- Capitalize annual time cost to determine value loss

**Example (industrial property)**:
- **Before**: Direct access to arterial road, 2-minute travel to highway interchange
- **After**: Taking eliminates direct access, requires 3 km detour via local roads, 8-minute travel to highway
- **Additional time**: 6 minutes each way = 12 minutes/day
- **Annual time cost**: 250 business days × 12 min/day × (1 hr/60 min) × $40/hr × 20 trips/day = $40,000/year
- **Capitalization**: $40,000 ÷ 7% cap rate = **$571,000 severance damage**

**Traffic count impact**:
- Loss of high-traffic frontage reduces commercial visibility
- Quantified as percentage reduction in sales/rent potential
- Example: Commercial property loses 15,000 vehicles/day frontage, gains 3,000 vehicles/day frontage → 80% traffic loss → 10-20% reduction in rent potential → capitalized value loss

### Landlocked Parcel Remedies (Easement Costs, Value Impact)

**Scenario**: Partial taking severs access, creating landlocked remainder with no legal access to public road.

**Remedies and costs**:

1. **Acquire access easement from adjacent landowner**:
   - Easement value: 10-15% of fee simple value for affected land
   - Legal costs: $15K-$30K
   - Survey and registration: $5K-$10K
   - **Total cost**: Easement value + $20K-$40K transaction costs

2. **Necessity easement (court-ordered)**:
   - Legal proceedings: $50K-$150K
   - Court-awarded easement compensation: 10-15% of fee simple
   - Delay and uncertainty (1-3 years)
   - **Total cost**: Easement value + $50K-$150K legal fees + time cost

3. **Value impact if no easement obtainable**:
   - Landlocked land: 50-80% reduction in value (agricultural use only via aerial/helicopter access for specialty crops)
   - Effectively sterilized for most development purposes

**Example calculation**:
- **Remainder**: 50 acres, agricultural use, $15,000/acre = $750,000
- **Access loss**: Landlocked, requires 200-meter easement across adjacent property
- **Easement cost**: 0.5 acres × $15,000/acre × 12% = $900 + $25,000 legal/survey = **$25,900**
- **Alternatively - value loss if no easement**: $750,000 × 60% reduction = **$450,000** (use lower if easement obtainable, higher if not)
- **Severance damage**: **$25,900** (cost-to-cure) or **$450,000** (value loss if no cure)

## Shape Irregularity

Valuing odd-shaped remainders resulting from takings that create inefficient parcel configurations.

### Geometric Efficiency Ratios (Area to Perimeter)

**Methodology**: Quantify shape inefficiency using area-to-perimeter ratio, comparing before/after taking.

**Optimal shapes** (efficient for development):
- **Square**: Area/Perimeter ratio = L²/4L = L/4 (maximum efficiency for rectangle)
- **Circle**: Area/Perimeter ratio = πr²/2πr = r/2 (theoretical maximum efficiency)
- **Regular rectangle** (2:1 ratio): Moderately efficient

**Inefficient shapes**:
- **Long, narrow strip** (10:1+ ratio): Very inefficient
- **Triangular**: Moderate inefficiency
- **Irregular polygon** (multiple angles, re-entrants): High inefficiency

**Efficiency index calculation**:
- **Efficiency Index** = (Actual Area ÷ Actual Perimeter) ÷ (Square Area ÷ Square Perimeter)
- Index = 1.0 = Perfect square efficiency
- Index = 0.8-1.0 = High efficiency (minimal value loss)
- Index = 0.6-0.8 = Moderate efficiency (5-10% value loss)
- Index = 0.4-0.6 = Low efficiency (10-20% value loss)
- Index <0.4 = Very low efficiency (20-40% value loss)

**Example**:
- **Before**: 100-acre parcel, roughly square (2,000 ft × 2,000 ft), perimeter = 8,000 LF
  - Efficiency Index = (100 acres ÷ 8,000 LF) ÷ (100 acres ÷ 8,000 LF) = 1.0
- **After**: 60-acre remainder, long narrow strip (400 ft × 6,000 ft), perimeter = 12,800 LF
  - Efficiency Index = (60 acres ÷ 12,800 LF) ÷ (Square 60 acres ÷ 7,760 LF) = 0.61
- **Shape inefficiency**: Moderate (0.6-0.8 range) → **8% value reduction**
- **Severance damage**: 60 acres × $15,000/acre × 8% = **$72,000**

### Development Yield Analysis (Buildable Area Calculations)

**Methodology**: Calculate reduction in developable units/area from shape constraints.

**Residential subdivision example**:

**Before**:
- 50 acres, regular shape, medium-density zoning (10 units/acre)
- Developable area: 50 acres - 15% (roads/parks) = 42.5 acres
- **Yield**: 42.5 acres × 10 units/acre = **425 units**
- **Value**: 425 units × $150,000/unit = $63.75M

**After (taking creates irregular remainder)**:
- 35 acres, irregular "L" shape with two narrow arms
- Developable area: 35 acres - 20% (roads/parks - higher % due to irregular layout) = 28 acres
- Inefficient lot layout: Many lots sub-standard depth or width
- **Yield**: 28 acres × 8 units/acre (reduced density) = **224 units**
- **Value**: 224 units × $150,000/unit = $33.6M

**Severance damage calculation**:
- **Before (proportionate)**: $63.75M × (35 acres ÷ 50 acres) = $44.625M
- **After**: $33.6M
- **Severance damage**: $44.625M - $33.6M = **$11.025M** (24.7% reduction)

**Alternative methodology (per-acre impact)**:
- Before: $63.75M ÷ 50 acres = $1,275,000/acre
- After: $33.6M ÷ 35 acres = $960,000/acre
- **Severance damage**: ($1,275,000 - $960,000) × 35 acres = **$11.025M**

### Comparable Sales of Irregular Parcels

**Methodology**: Market extraction showing discount for irregular shapes.

**Paired sales**:

**Sale 1** (regular shape):
- 20 acres, square configuration, zoned commercial
- Sale price: $80,000/acre = $1,600,000

**Sale 2** (irregular shape):
- 22 acres, long narrow strip (300 ft × 3,200 ft), zoned commercial
- Sale price: $65,000/acre = $1,430,000
- Time/location adjusted: $66,500/acre

**Shape discount**: ($80,000 - $66,500) ÷ $80,000 = **16.9% reduction** for irregular shape

**Application to subject**:
- Remainder: 40 acres, irregular after taking
- Comparable irregular sales: 15-20% discount
- Adopted shape discount: **17%**
- Fee simple value (if regular): $80,000/acre
- **Actual value (irregular)**: $80,000 × (1 - 0.17) = **$66,400/acre**
- **Severance damage**: $80,000 - $66,400 = **$13,600/acre** × 40 acres = **$544,000**

## Utility Impairment

Functional obsolescence from division - loss of highest and best use or reduced development potential.

### Loss of Highest and Best Use (Zoning-Permitted vs. Achievable)

**Scenario**: Taking reduces parcel size below minimum for zoning-permitted use, forcing less valuable use.

**Example (industrial subdivision)**:

**Before**:
- 100 acres, zoned "Employment - Prestige Industrial"
- Minimum lot size: 5 acres per zoning
- Highest and best use: Subdivision into 18 × 5-acre lots (10% for roads)
- Value: 18 lots × $500,000/lot = **$9,000,000** ($90,000/acre)

**After**:
- 65 acres remain (35 acres taken for highway)
- Still zoned "Employment - Prestige Industrial"
- **Problem**: Irregular shape yields only 10 × 5-acre lots (instead of proportionate 11.7 lots)
- **Alternative use**: General industrial (no minimum lot size) at lower value
  - Value as general industrial: 65 acres × $60,000/acre = **$3,900,000**
  - Value if could maintain prestige industrial subdivision: 11.7 lots × $500,000 = **$5,850,000**

**Severance damage**: **$5,850,000** (proportionate before value) - **$3,900,000** (after value) = **$1,950,000** (33% reduction)

### Reduced Development Potential (Unit Count, Parking Ratios)

**Scenario**: Taking creates site constraints that reduce developable area or building footprint.

**Example (commercial development)**:

**Before**:
- 10 acres, regular rectangle, highway frontage, zoned commercial
- Maximum lot coverage: 40%
- Parking requirement: 4 spaces/1,000 sq ft GLA
- **Buildable area**: 10 acres × 40% = 4 acres = 174,240 sq ft
- **Parking demand**: 174,240 ÷ 1,000 × 4 = 697 spaces
- **Parking area**: 697 spaces × 350 sq ft/space = 243,950 sq ft = 5.6 acres
- **Site capacity**: 174,240 sq ft building + 243,950 sq ft parking = 9.6 acres (fits)
- **Value**: 174,240 sq ft × $250/sq ft = **$43.56M**

**After**:
- 7 acres remain (irregular "L" shape after 3-acre corner taking)
- Buildable area still 40% coverage = 2.8 acres = 121,968 sq ft (theoretical)
- **Problem**: Irregular shape constrains building footprint to 90,000 sq ft maximum
- **Parking demand**: 90,000 ÷ 1,000 × 4 = 360 spaces
- **Parking area**: 360 spaces × 350 sq ft = 126,000 sq ft = 2.9 acres
- **Total requirement**: 90,000 sq ft building (2.07 acres) + 2.9 acres parking = 4.97 acres (fits, but reduced from potential)
- **Value**: 90,000 sq ft × $250/sq ft = **$22.5M**

**Severance damage calculation**:
- **Before (proportionate)**: $43.56M × (7 acres ÷ 10 acres) = **$30.49M**
- **After**: **$22.5M**
- **Severance damage**: $30.49M - $22.5M = **$7.99M** (26% reduction)

### Site Servicing Complications (Utilities, Drainage)

**Scenario**: Taking severs utility connections or disrupts drainage patterns, requiring costly remediation.

**Utility relocation costs**:
- **Water main relocation**: $300-$600/linear meter
- **Sanitary sewer relocation**: $500-$1,000/linear meter
- **Electrical distribution**: $200-$400/linear meter
- **Gas main**: $150-$350/linear meter

**Example**:
- Taking severs water and sewer connections to remainder
- Requires 400 meters of new water/sewer mains to reconnect
- **Cost**: 400m × $500/m (water) + 400m × $800/m (sewer) = **$520,000**

**Drainage disruption**:
- Taking alters grading, creating ponding/flooding on remainder
- Requires new storm sewer system or grading modifications
- **Cost**: Engineering $15K + construction $180K = **$195,000**

**Total site servicing severance**: $520,000 + $195,000 = **$715,000**

## Farm Operation Disruption

Agricultural severance impacts from field division, equipment access complications, and irrigation system impacts.

### Field Division Costs (Fence Installation, Drainage Modifications)

**Fencing costs** (to separate taking from remainder):
- **Agricultural fence** (4-strand barbed wire): $8-$12/linear meter
- **Page wire fence** (livestock): $15-$25/linear meter
- **Chain link fence** (6-foot, industrial): $80-$120/linear meter

**Example**:
- Taking bisects farm, requires 2,000 meters of new fence
- Livestock operation requires page wire
- **Fencing cost**: 2,000m × $20/m = **$40,000**

**Drainage modifications**:
- Taking disrupts tile drainage system serving 50 acres
- Requires new outlet and 1,500 meters of tile drainage to reconnect
- **Cost**: Engineering $8K + tile installation $15/m × 1,500m = **$30,500**

**Total field division costs**: $40,000 + $30,500 = **$70,500**

### Equipment Access Complications (Turning Radius, Crossing Points)

**Scenario**: Taking creates narrow or landlocked fields requiring circuitous equipment access.

**Time-cost analysis**:
- **Before**: 200-acre farm, efficient field layout, 2 large fields
- **After**: Taking bisects farm into two 100-acre parcels separated by highway
- **Equipment crossing**: Requires 5 km detour to move equipment between fields (no at-grade crossing)
- **Annual time cost**: 30 crossings/year × 5 km detour × 2 ways × 10 km/hr speed × $150/hr equipment+operator = $2,250/year
- **Capitalization**: $2,250 ÷ 7% cap rate = **$32,140**

**Turning radius constraints**:
- Narrow remainder field (150 meters wide) constrains large equipment
- Reduces efficiency by 15% (measured in time per acre)
- Annual cost: 50 acres × $40/acre operating cost × 15% = $300/year
- **Capitalization**: $300 ÷ 7% = **$4,280**

**Total equipment access severance**: $32,140 + $4,280 = **$36,420**

### Irrigation System Impacts (Pivot Circles, Distribution Lines)

**Center pivot irrigation disruption**:

**Scenario**: Taking bisects irrigated field, disrupting center pivot system.

**Before**:
- 160-acre field, 4 center pivots (40 acres each)
- Irrigation value: $2,000/acre premium for irrigated land
- Total irrigation premium: 160 acres × $2,000/acre = $320,000

**After**:
- Taking removes 30 acres, severs distribution lines to 2 pivots
- Remaining 130 acres: 2 pivots functional (80 acres), 2 pivots non-functional (50 acres)
- Non-functional pivots: Requires $180,000 to relocate distribution lines, pump station
- **Alternatives**:
  1. **Repair irrigation**: $180,000 cost to reconnect → 130 acres irrigated
  2. **Abandon irrigation**: 50 acres lose irrigation premium → $100,000 value loss

**Severance damage (cost-to-cure)**: **$180,000** (cost to repair irrigation system)

**Alternative severance damage (value loss if not repaired)**:
- Lost irrigation premium: 50 acres × $2,000/acre = **$100,000**
- Plus inefficiency/loss on remaining pivots: **$20,000**
- **Total**: **$120,000**

**Adopt lower**: **$120,000** severance damage (value loss approach, as owner may not repair)

---

## Calculator Usage

This skill includes a production-grade severance damages calculator with modular architecture.

### Command Line Usage

```bash
# Basic calculation
python severance_calculator.py input.json

# Specify output location
python severance_calculator.py input.json results.json

# Validate input first (recommended)
python validate_severance.py input.json
python validate_severance.py input.json --fix --output clean.json
python severance_calculator.py clean.json results.json
```

### Python API

```python
from severance_calculator import calculate_severance_damages, load_from_json

# Load from JSON
property_before, taking, remainder, market = load_from_json("input.json")

# Calculate
summary = calculate_severance_damages(
    property_before, taking, remainder, market
)

# Access results
print(f"Total severance damages: ${summary.total_severance_damages:,.2f}")
print(f"Access damages: ${summary.access_damages.total_access_damages:,.2f}")
print(f"Shape damages: ${summary.shape_damages.total_shape_damages:,.2f}")
print(f"Utility damages: ${summary.utility_damages.total_utility_damages:,.2f}")
print(f"Farm damages: ${summary.farm_damages.total_farm_damages:,.2f}")
```

### Input Format

See `severance_input_schema.json` for complete schema. Minimal example:

```json
{
  "property_before": {
    "total_acres": 10.0,
    "frontage_linear_feet": 500.0,
    "road_classification": "highway",
    "shape_ratio_frontage_depth": 0.25,
    "value_per_acre": 150000.0,
    "use": "commercial"
  },
  "taking": {
    "area_taken_acres": 1.5,
    "frontage_lost_linear_feet": 100.0,
    "creates_landlocked": false,
    "creates_irregular_shape": true
  },
  "remainder": {
    "acres": 8.5,
    "frontage_remaining_linear_feet": 400.0,
    "shape_ratio_frontage_depth": 0.20,
    "access_type": "direct"
  },
  "market_parameters": {
    "cap_rate": 0.07
  }
}
```

### Calculator Architecture

**Modular Structure** (Version 2.0.0):
```
severance-damages-quantification/
├── config/               # Centralized constants (zero magic numbers)
│   └── constants.py
├── damages/              # Specialized calculation modules
│   ├── access.py         # Access impairment (frontage, circuitous, landlocked)
│   ├── shape.py          # Shape irregularity (efficiency, buildable area, yield)
│   ├── utility.py        # Utility impairment (site servicing, development)
│   └── farm.py           # Farm disruption (fencing, equipment, irrigation)
├── models/               # Data structures
│   ├── property_data.py
│   ├── damage_results.py
│   └── market_parameters.py
├── utils/                # Shared utilities (safe_divide, capitalize_annual_cost)
│   └── calculations.py
├── tests/fixtures/       # Test scenarios
├── severance_calculator.py       # Main orchestrator (360 lines, was 943)
├── severance_input_schema.json   # JSON Schema validation
└── validate_severance.py         # Input validation with auto-fix
```

### Sample Scenarios

The calculator includes 5 tested scenarios in `tests/fixtures/`:

1. **highway_frontage_loss.json** - Highway frontage reduction (industrial)
2. **landlocked_parcel.json** - Complete access loss requiring easement
3. **irregular_shape.json** - Severe shape inefficiency from partial taking
4. **farm_bisection.json** - Agricultural corridor impact with field division
5. **combined_damages.json** - Multiple damage categories simultaneously

### Key Features

**Production Hardening**:
- ✅ Modular architecture (4 specialized damage modules)
- ✅ Zero magic numbers (all constants centralized)
- ✅ Defensive programming (safe_divide, capitalize_annual_cost)
- ✅ JSON Schema validation with auto-fix
- ✅ Comprehensive logging
- ✅ 100% backward compatible with Version 1.0.0

**Calculation Methodology**:
- USPAP 2024 compliant
- CUSPAP 2024 compliant
- Ontario Expropriations Act framework
- Before/after appraisal method

### Validation & Quality Assurance

```bash
# Validate input before calculation
python validate_severance.py input.json

# Common issues auto-fixed:
# - Missing optional fields (adds defaults)
# - Boolean/number type conversions
# - Market parameter defaults
```