Japanese Knotweed: What to do if you are buying a house

Recent research has detailed the major hotspots for the invasive plant Japanese Knotweed. But what do you do if you are due to buy a house?

Before buying a house it’s important to get a survey to know exactly how much work you need to do on the property,  says Compare My Move.

According to Environet, Japanese knotweed can reduce the value of your home by 10%.

Japanese knotweed can devalue your home because:

• it can damage your property or neighbouring properties

• left untreated it can spread and grow very quickly

• it is expensive to treat

• digging through dormant knotweed to build an extension can cause it to start growing again

• mortgage lenders are reluctant to lend on properties with knotweed

• it could lead to disputes with neighbours

• it can affect the aesthetics of your garden

Mortgage lenders differ in how they view Japanese knotweed. There isn’t an industry standard so each lender will have its own criteria.

However, RICS has five categories of knotweed problems. This will be outlined by a home survey if your property has Japanese Knotweed. Here’s how each case fits into this classification will affect your mortgage chances.

1 No Japanese knotweed is found on the property or those nearby.

2 There is no Japanese knotweed on the property, but it has been found on a neighbouring building or land more than 7 metres away from the boundary.

3 Japanese knotweed has not been found within the boundaries of the property, but it is present on a neighbouring property within 7 metres of the boundary but more than 7 metres from the habitable spaces of the property.

4 Japanese knotweed has been spotted within the boundaries of the property but it is more than 7 metres from the habitable space. Any damage to outbuildings, paths and fences is only minor. A Japanese knotweed survey is required.

5 Japanese knotweed has been spotted within 7 metres of a habitable space at the property. This could either be within the boundaries of a property or in a neighbouring property and/or Japanese knotweed has caused serious damage to outbuildings, paths and boundary walls.

If the knotweed falls into category 2 or 3, you may need a bigger deposit or a higher interest rate on your mortgage.

If the property is in category 4 or 5 you are likely to be refused a mortgage. If you are offered a mortgage, it’s likely to be dependent on a Japanese knotweed treatment plan being put in place.

If you are thinking of buying a house with knotweed you should:

• – Get a full building survey done by a RICS surveyor, including the garden

• – If knotweed is identified, get a Japanese knotweed survey done

• – Ask the seller if a treatment plan with indemnity insurance is in place

If the knotweed is not being treated, you could insist that the seller arrange and pay for treatment before you exchange contracts. However, some firms will only issue guarantees after completion of the treatment plan.

Alternatively, you could re-negotiate the property price. This could account for the cost of paying for a knotweed management plan yourself.

Once you own the home, the Anti-social Behaviour, Crime and Policing Act 2014 means you are obliged to control invasive plants on your property. You could be fined up to £2,500 if you don’t take action to control knotweed.

If your home is impacted by Japanese knotweed, it doesn’t necessarily mean you can’t sell it.

However, you must be honest. Sellers must legally disclose if they know knotweed is present on their property. You may face legal action if they deliberately try and cover up or conceal knotweed.

Legally, you need to state the property has knotweed on the TA6 Seller’s Property Information Form. If you lie on the form you could be sued for ‘misrepresentation’.

In most cases, you’ll need to pay upfront for a knotweed management plan and insurance-backed guarantee in order to sell your home. Without this, you may be limited to cash buyers.