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Invasive Plants Risk

Schedule 9 invasive plant risk for any UK property — Japanese knotweed, giant hogweed, Himalayan balsam, and four more species. Sourced from the National Biodiversity Network Atlas, searched within a 5-mile radius. Returns a risk label and recorded sighting count per species.

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Species risk at a glance

Seven results — one per species. Each result includes a proximity-based risk label and the number of recorded sightings within a 5-mile radius from the NBN Atlas database.

UPRN 200001234567 — Invasive Plants

Rural Berkshire — within 5 miles of river

risks/invasive_plants

Japanese knotweed High

12 sightings · 5mi radius Affects mortgage lending. Most closely monitored species.

Giant hogweed Low-Medium

3 sightings · 5mi radius Health hazard — toxic sap causes severe burns.

Himalayan balsam Medium

8 sightings · 5mi radius Riverbank species, spreads rapidly.

Rhododendron ponticum Not detected

0 sightings · 5mi radius

+ 3 more species (Floating pennywort, New Zealand pygmyweed, Cotoneaster) — all Not detected for this property.

Risk labels by proximity

Urgent Within 50m

Very High 50–250m

High 250m–1km

Medium-High 1–2km

Medium 2–3km

Low-Medium 3–5km

Low 5–8km

Not detected No sightings

Response fields

Returns exactly 7 results — one per species. Species with no sightings within 5 miles return label: "Not detected" and count: 0.

risk_type string "invasive_plant_japanese_knotweed" (and 6 other species slugs)

label string Urgent / Very High / High / Medium-High / Medium / Low-Medium / Low / Not detected

score integer Number of sightings within 5-mile radius

score_unit string "records"

intersects boolean True if sightings found within 50m (Urgent band)

distance_m integer|null Distance to nearest sighting in metres. null if not detected

search_radius_m integer 8050 — 5-mile NBN Atlas search radius

count integer Total sighting records within 5 miles

radius_description string "Within 5 miles"

7 species covered

1. Japanese knotweed (mortgage-critical)

2. Giant hogweed

3. Himalayan balsam

4. Rhododendron ponticum

5. Floating pennywort

6. New Zealand pygmyweed

7. Cotoneaster

Built for

Mortgage lending

Japanese knotweed within 7 metres of a structure can affect mortgage offers. Most high-street lenders have specific criteria. Pre-screen applications by proximity band before instructing a surveyor.

Surveyors & valuers

Flag high-risk properties before a site visit. The API gives you sighting count and distance — enough context to decide whether a knotweed-specific survey is warranted.

Property search platforms

Surface knotweed risk alongside EPC and flood data in your property detail view. Buyers increasingly research this before arranging viewings — useful signal for engagement.

API example

GET /api/risks/invasive_plants/?uprn= cURL

curl "https://api.homedata.co.uk/api/risks/invasive_plants/?uprn=200001234567" \
  -H "Authorization: Api-Key YOUR_KEY"

Response (truncated) 200 OK

{
  "risk_type": "invasive_plants",
  "uprn": 200001234567,
  "results": [
    {
      "risk_type": "invasive_plant_japanese_knotweed",
      "label": "High",
      "score": 12,
      "score_unit": "records",
      "intersects": false,
      "distance_m": 620,
      "search_radius_m": 8050,
      "count": 12,
      "radius_description": "Within 5 miles",
      "properties": {
        "description": "12 records within 5mi"
      }
    },
    {
      "risk_type": "invasive_plant_rhododendron_ponticum",
      "label": "Not detected",
      "score": 0,
      "count": 0,
      "distance_m": null
    }
    // ... 5 more species
  ]
}

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