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Did you know that if you have Japanese Knotweed on a property or even nearby, it is now necessary for a mortgage provider to have a Japanese Knotweed Survey and Management Plan before they agree to lend...

As a member of the Property Care Association and a 'Certified Surveyor of Japanese Knotweed', Andrew Spencer from Complete Weed Control (West Wales) is authorised to provide these latest requirements to the mortgage process.

Information on Japanese Knotweed and Mortgages

Mortgage companies will no longer allow mortgages on properties with Japanese Knotweed infestations without certain procedures in place. The closer to the property, the more stringent the mortgage companies become.

Below is the table used by Surveyors to determine the Risk Category for the Japanese Knotweed on a particular property. As you can see even if you have no Japanese Knotweed but your neighbour has it could still be a problem!


If a mortgage is not required to buy a property then these procedures and stipulations are not mandatory or necessarily required, however the purchaser will probably want the seller to contribute or pay for the Japanese Knotweed treatment.

Whilst having Japanese Knotweed on your land does not contravene the law you are legally obliged to stop it spreading from your property elsewhere.

The following information is from my personal experience and should not be counted on as correct for every situation. You should always liaise with your estate agent, surveyor and Mortgage Company, if known, before making your decision on which course of action to take.

  1. If a treatment programme is already in place and ongoing a mortgage company may well accept that and grant the mortgage if a full report is supplied by the contractor carrying out the work.
  2. Properties with Japanese Knotweed present and not being treated by a specialist contractor will require a Japanese Knotweed Survey and Management Plan before a mortgage is normally granted.
  3. An Insurance Backed Guarantee of five or ten years may also be required, these must be applied for before treatment begins and must be accompanied by a Japanese Knotweed Survey and Management Plan. This covers continuation of the treatment programme should the contractor be unable to fulfil their obligation, or if the Japanese Knotweed reappears some years later.
  4. If a Japanese Knotweed Survey, Management Plan and Insurance Backed Guarantee are required, the cost including the treatment programme must be paid up front. Make sure you choose a reputable contractor with a track record.

Japanese Knotweed can take several years to eradicate with herbicides, there is no such thing as a quick fix unless you are willing to foot the expense of excavation and disposal at a licensed controlled waste tip! Patience is a virtue with Japanese Knotweed, as is ‘Do Not Disturb’.

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