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Do Surveyors Look for Japanese Knotweed?

Japanese Knotweed surveyor

Do Surveyors Look for Japanese Knotweed?

Japanese Knotweed (Fallopia japonica) is a highly invasive plant that causes serious problems for property owners across the UK. Its powerful rhizome (root) system can invade gardens, damage hard surfaces, and weaken building foundations. Because of these risks, many buyers and homeowners naturally ask:

“Do surveyors check for Japanese Knotweed during a property inspection?”

Let’s break down what standard surveyors actually do, when specialist surveys become essential, and why knotweed identification matters so much in property transactions.

Do Standard Surveyors Look for Japanese Knotweed?

Most of the time, no. Standard surveys—such as Homebuyer Reports or Level 2 and Level 3 Building Surveys—mainly assess:

  • Structural integrity

  • Damp

  • Drainage

  • Roofing issues

  • Plumbing and electrics

  • General defects

Although surveyors may note visible vegetation, they do not carry out a detailed check for invasive plants.

However, if a surveyor spots something suspicious, they will usually:

  • Flag the potential risk

  • Recommend a specialist inspection

  • Advise the buyer to investigate further before proceeding

Even so, identifying Japanese Knotweed is not a guaranteed part of standard surveys. That’s why relying on a general survey alone often leads to missed problems.

Why You Need a Specialist Japanese Knotweed Survey

Japanese Knotweed can be easy to overlook unless you know exactly what to look for. Specialist surveyors have the training to identify subtle signs, even when the plant isn’t fully grown.

A specialist Japanese Knotweed survey provides a much more accurate assessment of the garden, boundaries, and surrounding land.

Specialists check for:

✔ Distinctive Above-Ground Growth

Features such as:

  • Bamboo-like hollow stems

  • Zig-zag shaped branches

  • Heart-shaped leaves

  • Crown formations and dead canes

✔ Underground Rhizomes

The roots often extend several metres underground. A specialist knows where knotweed typically spreads and how to trace it.

✔ Surrounding Risks

Since knotweed often spreads from:

  • Railway embankments

  • Watercourses

  • Waste ground

  • Neighbouring gardens

A thorough survey includes an inspection of nearby land as well.

Because of this detailed approach, a specialist survey offers far more certainty than a general inspection.

Legal and Financial Consequences of Japanese Knotweed

Japanese Knotweed comes with serious responsibilities. Under the Wildlife and Countryside Act 1981, landowners must prevent it from spreading into the wild. If they ignore the issue, they may face:

  • Fines

  • Legal action

  • Compensation claims from neighbours

Mortgage lenders also take knotweed seriously. Many lenders refuse mortgages unless:

  • A professional management plan is in place

  • A PCA-accredited specialist confirms the treatment

  • An insurance-backed guarantee is included

This makes early identification extremely important for sellers, buyers, and landlords.

What Happens During a Japanese Knotweed Survey?

A professional Japanese Knotweed survey includes several detailed steps:

1. Inspection and Identification

A specialist walks the entire site and uses experience to spot the plant, even in its early stages or winter form.

2. Mapping the Infestation

They record the above-ground growth and estimate the size and depth of the underground rhizome system.

3. Risk Assessment

The surveyor evaluates structural risks, boundary issues, and the likelihood of further spread.

4. Recommended Control Measures

Depending on the severity, they may recommend:

  • Herbicide treatment

  • Excavation

  • Soil screening

  • Root barriers

  • Long-term monitoring

5. Legal Compliance Advice

You’ll receive guidance on your legal responsibilities to prevent further spread and meet lender requirements.

After the inspection, you receive a written report that outlines the findings and the next steps.

Why Standard Surveyors Sometimes Face Legal Action

Standard surveyors sometimes overlook knotweed during property inspections. When this happens, legal consequences can follow.

Here is a well-known example:

Case Study: Ryb v Conways Chartered Surveyors (2019)

Background

In 2014, Paul Ryb purchased a £1.2 million flat in Highgate, North London. He ordered a Level 3 RICS Building Survey before completing the purchase.

Survey Findings

The surveyor reported that the property was in excellent condition and advised the buyer to proceed. No knotweed was mentioned.

Discovery

One year later, Japanese Knotweed appeared in three different locations on the property. The maturity of the plants clearly showed they had been present for several years, meaning the surveyor should have identified them in 2014.

Legal Action

Mr. Ryb sued the surveyor for negligence, claiming losses for:

  • Removal costs

  • Property devaluation

  • Legal fees

Outcome

The court ruled in Mr. Ryb’s favour and awarded him £50,000 in damages, plus additional legal costs.

Key Lessons

This case highlights several important points:

  • Surveyors have a duty of care to report visible knotweed.

  • Failing to do so may lead to negligence claims.

  • Proper documentation protects both the surveyor and the buyer.

  • Knowledge of invasive species is now considered essential for surveyors.

Recent Legal Cases Involving Landowners

It’s not only surveyors who face consequences. Landowners can also be fined for failing to control knotweed.

✔ Bradford, 2023

James Daniel Bateman from Hull was fined over £2,600 after repeatedly failing to remove knotweed from a site in Bradford. Authorities had warned him several times since 2019, but he still ignored the issue.

✔ Bradford, 2018

Another landowner in Wibsey received a £1,000 fine for allowing knotweed to spread on his land. The infestation threatened neighbouring homes, and despite repeated warnings, he never cleared the site.

These cases show how seriously councils treat uncontrolled knotweed.

Should You Rely on a Standard Survey?

In short: No.
Standard surveys rarely check gardens thoroughly and often miss knotweed.

For complete peace of mind, you should always hire a specialist Japanese Knotweed surveyor—especially if you are:

  • Buying a property

  • Selling a property

  • Managing rental properties

  • Concerned about a plant in your garden

A specialist survey saves time, prevents legal issues, and protects your investment.

Final Thoughts

Japanese Knotweed poses serious risks to property owners, buyers, and surveyors. Standard surveys don’t reliably detect it, so relying on them alone leaves you vulnerable to costly surprises.

A professional Japanese Knotweed survey gives you clear answers, a full risk assessment, and a realistic plan of action. With early detection, you avoid legal trouble, prevent neighbour disputes, and protect your property’s value.

Need Expert Help Identifying Japanese Knotweed?

If you’re unsure whether a plant on your property is Japanese Knotweed, don’t take chances.

📞 Call Stephen today on 07753 682333
PCA-Accredited Japanese Knotweed Surveyor
Japanese Knotweed Plus Ltd

He provides:

  • Free identification

  • Expert surveys

  • Mortgage-approved management plans

  • Insurance-backed guarantees

👉 Click below to read my Google reviews and see what clients say.

 

 

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