Selling a House with Japanese Knotweed in London

Selling a London house with Japanese knotweed is now routine, provided you handle the disclosure honestly and produce the documentation buyers' lenders expect. The mistakes that derail sales are almost always made on the TA6 form, not in the garden.

The TA6 Question

Question 7.8 of the standard TA6 Property Information Form asks: 'Is the property affected by Japanese knotweed?' The answers are Yes / No / Not Known. Answering 'No' when the answer is 'Yes' is misrepresentation and exposes you to a damages claim from the buyer post-completion.

Answering 'Not Known' Honestly

'Not Known' is a defensible answer only if you have not seen the plant and have no reasonable basis to suspect it. If a previous survey, neighbour notification or contractor visit has flagged knotweed, you must answer 'Yes'.

What Buyers Will Need

Most buyers' lenders will accept the property with a written invasive species management plan and an insurance-backed guarantee. Have these ready before going to market, they shorten the sale by weeks.

Pricing the Knotweed Adjustment

Expect to discount the asking price by the cost of treatment plus a small risk premium, typically 2% to 5% of property value. With documentation in place, the discount can be minimal.

Speeding Up Slow Sales

Commission the survey before listing, draft the management plan in advance, and provide both to interested buyers in the initial information pack. Sellers who do this routinely close at full market price.