It’s no secret that Japanese knotweed is a pesky weed. It can grow anywhere, it’s difficult to get rid of, and it spreads quickly. So you might be wondering: do surveyors check for Japanese knotweed before conducting a property survey?

The answer, unfortunately, is no. While some surveyors may have knowledge of how to identify Japanese knotweed, there is no formal certification or training required in order to become a surveyor in the UK. As such, it’s ultimately up to the individual surveyor whether or not they choose to look for Japanese knotweed on a property.

Does a survey check for knotweed?

Notwithstanding the fact that Japanese knotweed infestation has been known to cause a significant negative impact on the property market, you will still come across cases of surveyors missing to take note of the presence of the knotweed in an area whilst conducting surveys of the property. 

Whenever this happens, it is the buyer of the property that stands in a precarious position because they stand to suffer damages from the investment made owing to the late discovery of the knotweed.

Strictly speaking, it is a surveyor’s work to check for Japanese knotweed on the property and report on it. Based on the foregoing, this article will look deeper into the work of surveyors in relation to the discovery of Japanese knotweed on a property.

When confronted by a property such as this, clearly a surveyor would perform a Japanese knotweed survey to suggest a treatment plan
When confronted by a property such as this, clearly a surveyor would perform a Japanese knotweed survey to suggest a treatment plan


Across the UK, the Royal Institution of Chartered Surveyors (RICS) is a proficient body that promotes and enforces high standards in the valuation, management and development of land.

Qualified surveyors under this body are educated on how to detect an invasive plant such as the knotweed hiding in large masses of vegetation or isolated somewhere within a piece of land.

The surveyors registered under this body are supposed to be updated on any risk factor that could possibly lead to a Japanese knotweed infestation.

The RCIS further provides material to enable the surveyors to conduct proper inspections of the property with the purpose of discovering the invasive weed plant.

In order to properly identify a Japanese knotweed infestation, the ‘7-metre rule’ applies in the valuation process.

In a simplified manner, where the weed plant is growing within 7 metres from one’s property, further investigations are required; where the weed plant is outside the 7-metre rule then the surveyor has the liberty to decide whether it is potentially harmful to your property and recommend the right treatment plan.

Picking up the presence of Japanese knotweed

Whether or not a surveyor can easily identify an infestation of Japanese knotweed depends on the level of scrutiny that one opts for, the severity of the infestation, the professionalism of the survey exercise and the concealment of the knotweed by the owner of the property.

It is important to understand that all surveys are not carried out on the same standard. Each survey is cut to fit a certain budget and cost that clients chose. This is to mean, that the higher the cover for a survey, the more meticulous the results and vice versa is true.

Can a mortgage valuation identify Japanese knotweed?

A mortgage valuer does not bear greater responsibility in identifying Japanese knotweed as compared to a registered surveyor. The purpose of a mortgage valuation survey is to validate that the money the lender is giving is in accordance with the value of the property.

Therefore, do not pay for a mortgage valuation survey and assume that it will cover the identification of the Japanese knotweed found on your property.

The need for a Japanese knotweed survey to ascertain the extent of the problem and propose a treatment plan
The need for a Japanese knotweed survey to ascertain the extent of the problem and propose a treatment plan

Surveyors’ missing to identify the Japanese knotweed

Although not rampant, there are cases where surveyors miss to identify the existence of Japanese knotweed on property albeit not acting negligently. This can be influenced by a number of factors including:

Dishonesty from homeowners

It is commonplace to find homeowners that want to conceal the presence of the knotweed so that the sale of such a property is not hampered.

Taking into account that the presence of the knotweed is likely to derail the selling of the property, homeowners try to evade this huddle by being dishonest to the surveyor regarding the knotweed.

Despite surveyors’ being professional at what they do, a Japanese knotweed survey sometimes is dependent on the word of mouth of the seller, especially where the knotweed is not visible to the naked eye.

There are various ways that a homeowner can use to conceal the knotweed including but not limited to cutting down the weed plant, burying the shoots with wood chips etcetera.


It is possible to have a misidentification of the knotweed where the plant cannot be clearly identified. For instance, deformed growth due to poor treatment mechanisms may cause a misidentification.

Sometimes, it is possible to find that the weed plant is in its dormant phase after being subjected to a treatment program that did not work and hence leads to misidentification.

Underneath growth

In cases where the knotweed is growing underneath a building whether for reasons that the knotweed has been dispersed into the earth and is not visible to the naked eye.

Taking note that the rhizomes can still survive underground, this means a potential growth will occur at a later stage that may not be identified by a surveyor.

Overgrown gardens are a perfect breeding ground for this knotweed - get a Japanese knotweed survey to eradicate it permanently before it consumes your property
Overgrown gardens are a perfect breeding ground for this knotweed – get a Japanese knotweed survey to eradicate it permanently before it consumes your property

The course of action if a surveyor misses identifying Japanese knotweed

In the event that a surveyor misses identifying the growth of the Japanese knotweed in a survey before the property is purchased, any potential buyer entering into a deal to purchase the property through the reliance of such misrepresentation of the surveyor can maintain a legal action on such a misrepresentation.

Here, the buyer will be seeking damages for compensation to cover the costs that the buyer will incur in putting in place a treatment plan to eradicate the knotweed.

Equally, taking into account that the discovery of the Japanese knotweed can lead to the depreciation of the value of the property and the possible denial of access to mortgage lending, a Japanese knotweed survey if not done properly can grossly affect the sale of a house and loss of investment.

Noting that this misrepresentation results in damage, one can successfully bring a claim for professional negligence.


Do Surveyors Check For Japanese Knotweed?

The presence of Japanese knotweed on any property whether it is a small or large infestation is a ticking time bomb. It is important that when you hire a surveyor they do a meticulous job in identifying the knotweed in your property and appraise the cost of the treatment plan.

Failure of a surveyor to do their job correctly may expose them to legal action that would result in compensation for any misrepresentation. Finally, a Japanese knotweed survey is a key before any property is sold as it will help avoid any future legal implications for the negligent party.

Want to know more about undertaking a Japanese Knotweed survey?

Knotweed Removal aims to provide the most up-to-date information, help and advice for YOU to make informed decisions. If you are unsure or uncertain about how to proceed, please reach out to us and we will gladly come back and advise you as best we can.

Governmental advice can be found here and the UK law covering the removal of Japanese Knotweed as stated under the Wildlife and Countryside Act 1981 can be found here.

The best means to contact us is via our email –

Do not forget we have a library of blogs covering many areas relevant to Japanese Knotweed, our free downloadable How-to Guides and Product Reviews on the latest methods being employed to eradicate or remove Japanese Knotweed.

Knotweed Removal, UK

Similar Posts