It is absolutely possible to sell a property with Japanese knotweed, but the impact of having an invasive plant species can make the sale a little more complex, depending on the extent of the growth and whether it’s caused structural damage.
On average, reports suggest that the presence of knotweed can impact the sale value of a home by around 5% [1], but this could vary significantly depending on how long the plant has been there and whether it’s been treated.
Some sellers find that knotweed affects their valuation, the likelihood of a buyer being approved for a mortgage, and even the interest they see from buyers worried about the costs of putting the issue right, but this all comes down to the sales approach they choose.
Key takeaways
There is no restriction on selling a property with Japanese knotweed, but there is an obligation to declare its presence on information forms and disclosures.
Knotweed can affect property values and the ease of obtaining a mortgage, which is why professional treatment may be advisable to improve salability.
Sellers are advised to be fully transparent to avoid any issues or delays, and to weigh up the costs of removing knotweed with the implications for their planned sale.
Why Does Japanese Knotweed Impact Property Sales?
Japanese knotweed is an invasive plant that can grow very quickly, sometimes causing damage to walls, driveways and patios. While, despite misconceptions, it can’t grow through concrete, the plant can cause costly repairs and make its way into cracks and vulnerable points within property structures.
The main concerns for buyers are typically:
That knotweed might be expensive to treat and keep under control
Knotweed could impact the structural integrity of walls
There might be risks of the knotweed spreading to neighbouring homes
Mortgage lenders can have issues with financing homes with knotweed
Buyers, and often their solicitors, will normally want to investigate the property’s history and review the extent of knotweed growth before proceeding – although sellers can also consider selling through alternative methods like a property auction.
What Are the Rules for Selling a Property With Japanese Knotweed?
Sellers are legally required to disclose the presence of Japanese knotweed before a property sale, normally through a form called a TA6 Property Information Form, which sets out details like:
Whether knotweed is present
If it’s been treated and, if so, how and when
Failing to disclose Japanese knotweed can have consequences, such as the buyer taking legal action for misrepresentation or financial compensation, which is why it’s so important to share all the information the seller has in the property particulars.
However, another myth is that you can’t sell a home with knotweed, or that it makes an otherwise stable home or investment project unsellable, which simply isn’t true.
How Can Japanese Knotweed Impact a Property Sale?
Extensive knotweed that hasn’t been treated is far more likely to impact the valuation of a property, but that will depend on how established the invasive plant is, whether it’s already been treated, and whether it remains under control.
Factors that will dictate how much knotweed influences a valuation include:
The severity of the infestation
How close the knotweed is to the building
When and how the knotweed has been treated
Whether there are any guarantees or insurances available
There are sets of guidelines governing how properties with Japanese knotweed are valued, and these have been updated in recent years to ensure surveyors apply fair treatment based on the risk posed. [2]
Importantly, these guidelines include a structured assessment framework (often referred to as a decision tree) that surveyors use to evaluate risk when creating an auction property valuation. This helps ensure properties are assessed consistently and avoids outdated assumptions about the severity of Japanese knotweed.
How Can Owners Sell a Home With Japanese Knotweed?
There are several ways to approach a property sale, and although knotweed can complicate matters, sellers can improve their prospects of selling successfully by:
Arranging a professional survey to assess whether there is a risk to the structure of the building, and provide recommendations for the best treatment.
Organising a treatment plan, where relevant, noting that these are often ongoing for several years, from herbicide treatments to follow-up interventions.
Declaring everything that is known about the knotweed in all forms and documents, and being available to answer questions to address uncertainties.
Another option for sellers is to consider a property auction, where a proportion of bidders are experienced buyers with greater property management experience and who are often less risk-averse.
The benefits of an auction include a fixed timeframe for completion and the ability to sell the property ‘as seen’, with the disclosed information.
Buyers and developers aren’t always put off by knotweed but might see an opportunity to acquire a property at a competitive value and treat the invasive plant themselves.
Key Contrasts to Be Aware of When Selling a Property With Managed vs Unmanaged Knotweed
Scenario | Potential Impact on the Sale |
No treatment plan in place | Can increase perceived risk and reduce buyer interest |
Treatment plan in progress | Improved buyer confidence |
Insurance-backed guarantees | Greater interest and acceptance by financiers and lenders |
Knotweed that is severe or close to the property | Potential issues selling on the open market due to mortgage complications |
Clive Emson notes that ‘Japanese knotweed doesn’t necessarily mean a property is hard to sell, but the issues are often around how knotweed is perceived, rather than its real-world impact on the value and stability of a property.
Buyers tend to be worried about costs, the risks of the knotweed spreading, and whether it’s already been professionally managed, which is why providing full disclosures and, where applicable, initiating a treatment plan can make a big difference.
Auction buyers who may have experience managing knotweed, or who plan to renovate or refurbish a property, are less inclined to consider knotweed a dealbreaker, and more of a factor that will enable them to acquire a new property at a competitive price.’
Ultimately, while Japanese knotweed can present a challenge, a well-prepared and transparent approach can ensure a successful sale, particularly when sellers understand their options and choose the right route to market.
Frequently Asked Questions
Can I Sell My Home if I Have Japanese Knotweed?
Yes, without a doubt, although being clear about the extent of the growth and how it’s been treated thus far is essential.
How Long Does it Take to Get Rid of Japanese Knotweed?
Knotweed is resilient, which is why a one-off treatment doesn’t always solve the problem. However, sellers who have started treatment and can share how often the knotweed is inspected will often find it easier to sell.
Complete eradication can take several years, but treatment plans can control and manage the plant, which is often sufficient for buyers and mortgage lenders.
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