POST
/
benchmark
Create a benchmark report using the standard model
curl --request POST \
  --url https://api.n-3.co.uk/benchmark \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
  "total_gifa": 1500000,
  "individual_units": 12,
  "site_area": 15000,
  "location_index": 115,
  "start_date": "2024-11-01",
  "total_net_internal_area": 1000,
  "site_max_floors_above_ground": 2,
  "site_max_floors_below_ground": 1,
  "detached_garage_spaces": 0,
  "basement_parking_spaces": 0,
  "integral_garage_spaces": 0,
  "undercroft_parking_spaces": 0,
  "car_ports": 0,
  "surface_parking": 0,
  "primary_building_function": "residential",
  "primary_building_process": "new_build",
  "procurement_arrangements": "main_contractor_design_build",
  "demolition": 0,
  "contaminated_soil_removal": 0,
  "piling": 0,
  "basement_construction": 0,
  "structural_alterations": 0,
  "concrete_frame": 0,
  "lift_escalator": 0,
  "retaining_walls": 0,
  "diversion_of_services": 0,
  "drainage_pumping_station": 0,
  "electricity_sub_station": 0,
  "sprinkler_system": 0,
  "party_wall": 0,
  "balconies_terraces_winter_gardens": 0,
  "basement_car_parking": 0
}'
[
  {
    "totals": 2571000,
    "external_works_variation": 100000,
    "total_including_external_works": 2571000,
    "total_adjusted_value": 2991359,
    "adjusted_cost_per_m2": 1994,
    "lower_limit": 1595,
    "upper_limit": 2592,
    "_meta": {
      "adjustment_percentage": 0.35,
      "external_works_percentage": 0.25,
      "strength": 75,
      "profiled_strength": 2.5,
      "location": {
        "county": "London",
        "index": 100
      }
    }
  }
]

​
Overview

Generates a comprehensive benchmark report using N3’s standard cost prediction model. This endpoint creates cost forecasts based on similar projects, providing statistical analysis with confidence intervals.

​
Benchmark Types

Supports multiple benchmark approaches:
  • STANDARD - Single development benchmarking
  • COMPOSITE - Multi-development project analysis
  • PARTIAL - Individual development within composite projects

​
Model Capabilities

​
Cost Prediction Features

  • Statistical modeling using 50+ weighted factors
  • Confidence intervals (typically 75-85% confidence)
  • Real-time prediction updates
  • Quality assessment and validation

​
Input Requirements

  • Project characteristics (GIFA, location, features)
  • Development type and building specifications
  • Site constraints and procurement details
  • Budget data and timeline information

​
Quality Assessment

Benchmarks are evaluated through multiple quality checks: ✅ Data Completeness - Presence of out-turn cost data
✅ Statistical Validity - Average costs within confidence intervals
✅ Similarity Threshold - Combined scores ≤30 points for 3 projects
✅ Geographic Relevance - Location and time index alignment

​
Usage Examples

​
Standard Benchmark Request

{
  "projectId": "12345",
  "benchmarkType": "STANDARD",
  "includeComparisons": true,
  "generatePredictions": true
}

​
Composite Project Request

{
  "projectId": "12345", 
  "benchmarkType": "COMPOSITE",
  "developments": ["dev1", "dev2"],
  "hybridSupport": true
}

​
Response Structure

Returns comprehensive benchmark data including:
  • Cost predictions with confidence ranges
  • Similar project comparisons and scores
  • Quality indicators and health ratings
  • Statistical model metadata

Authorizations

​
x-api-key
string
header
required

Body

application/json

Response

200 - application/json

The response is of type object[].