Selling a house with Japanese knotweed

At SE Knotweed, we help you sell a house with knotweed by producing the survey, plan and guarantee a buyer’s lender needs, and the TA6 form requires you to declare it, answering No to question 7.8 only if you are certain none is within 3 metres of the boundary.

Can I sell a house with Japanese knotweed?

At SE Knotweed, we confirm you can sell a house with Japanese knotweed, and most sales complete once a survey, a management plan and an insurance-backed guarantee are in place, because that package lets the buyer's lender lend against the property.

An untreated stand with no plan is what stalls a sale, not the plant itself. We produce the documents a buyer, a solicitor and a valuer need, so the transaction can proceed while treatment continues. Get in touch if a sale has stalled over knotweed.

Do I have to declare knotweed when selling?

You do have to declare Japanese knotweed when selling, because question 7.8 of the TA6 Property Information Form asks specifically whether the property is or has been affected by it, and answering falsely can found a misrepresentation claim after completion.

The duty is one of honesty on the form, not a duty to treat before you sell. An answer supported by a survey protects you, because it shows you replied on a proper basis.

How do I answer TA6 question 7.8 honestly?

You answer TA6 question 7.8 honestly by ticking Yes if knotweed is or has been present, and you may only answer No if you are certain there is no rhizome above or below ground on the property or within 3 metres of the boundary, a standard tightened in the 2020 revision of the form.

If you are unsure, the honest answer is Not Known, and a survey turns that into a confident Yes or No. Answering No without certainty is the mistake that leads to a claim.

What documents does a buyer’s lender need?

A buyer's lender needs a specialist survey recording the RICS category, a management plan setting out the treatment and monitoring, and an insurance-backed guarantee that funds further treatment if the plant returns within the term.

Together these let the valuer lend against the property. We produce the survey and management plan, and set out the insurance-backed guarantee an audited contractor issues.

Does knotweed reduce what I can sell for?

Knotweed can reduce what you sell for while it is untreated, because a buyer and their lender price in the treatment cost and the risk, but a completed plan and an insurance-backed guarantee usually restore most of the value.

The residual effect is often smaller than owners fear once the risk is underwritten. Our diminution in value page explains what the courts have said about the fall in value and what can be recovered.

What happens if I do not declare it?

If you do not declare known knotweed and answer No to question 7.8, the buyer can bring a misrepresentation claim after completion, seeking damages and in some cases rescission of the sale, because they relied on a false statement about the property.

Several reported cases have turned on a seller answering No when they knew of a stand. A truthful answer supported by a survey is the protection, which is why we advise surveying before you complete the form.

Should I treat the knotweed before I sell, or leave it to the buyer?

Whether to treat before selling or leave it to the buyer depends on your timescale: putting a plan and guarantee in place before marketing gives buyers confidence and can protect the price, while a motivated buyer may accept an assignable plan and complete sooner.

Because the guarantee can transfer, treatment need not finish before completion. We can set the plan up so it assigns cleanly to the buyer, and advise which route suits your sale.

How quickly can you get me sale-ready?

We can usually survey the property and issue the report and costed plan within a week, which is often enough for a buyer's lender to proceed, and faster where a chain is under pressure.

The treatment then continues after completion under the guarantee. Send us the address and your target completion date and we will tell you what is achievable.

Common questions

Can I sell a house with knotweed at auction?
Yes. Auction buyers are often cash purchasers who accept the plant, though a survey and plan still help the price. Declaring it in the legal pack is essential.
Does a cash buyer need the insurance-backed guarantee?
A cash buyer does not need it for a lender, but many still want it, because they may sell to a mortgaged buyer later and the guarantee protects that onward sale.
Who pays for treatment, the buyer or the seller?
It is a matter of negotiation. Sellers often fund the plan to protect the price, but a buyer may take it on in return for a price reduction. The assignable guarantee makes either route workable.
Do I have to declare knotweed that is only on a neighbour's land?
If knotweed sits within 3 metres of your boundary you cannot safely answer No to 7.8, even if the source is next door, so it should be disclosed and recorded by survey.

Book a survey and get a costed plan

Tell us the address and what a surveyor flagged. We confirm the plant, record the RICS category and set out the figures.

Book a survey
Call 01924 944600