Family devastated after house sale falls through at last minute and £20,000 is wiped off value... because Japanese knotweed is growing on council land behind their garden

• Ben Metcalfe, 35, had his mid-terrace home on market for two years
• Surveyor said property in Stockport, Greater Manchester, is worth £80,000, not £100,000 because of aggressive weed
• Plant can grow to 12ft tall, push through concrete and damage buildings
• Costs £100 per square foot to eradicate with pesticides

By Nick Enoch

A homeowner has had £20,000 wiped off the value of his family home - after a surveyor said it was under threat by Triffid-like weeds growing behind his back garden.
Father-of-one Ben Metcalfe, 35, had put his two-bedroom mid-terrace property on the market at £100,000 and after two years thought he had got a buyer.
But the sale fell through at the last minute after a surveyor who carried out a report on behalf of the prospective purchaser said it was only worth £80,000 because of a cluster of aggressive Japanese knotweed growing on council land in an alleyway.

Ben Metcalfe stands next to Japanese knotweed in the alleyway at the rear of his property in Edgeley, Stockport in Greater Manchester. A large clump of the weed can be seen directly behind him

The sale of Mr Metcalfe's house fell through at the last minute after a surveyor who carried out a report for a prospective purchaser said it was only worth £80,000 - not £100,000 - because the aggressive weed was growing on council land in an alleyway. The bamboo-like weed looms menacingly over the wall to the right

Mr Metcalfe, an NHS support worker, has been left devastated after the collapse of the sale. Pictured above with his family

The expert said the weed was a threat to foundations of neighbouring properties, in Stockport, Greater Manchester, and recommended a 'migration plan' to establish where the roots were, how fast it grows and the most likely direction it would grow in.
The bamboo-like plant can grow up to 12ft tall, push through concrete and damage buildings and it costs £100 per square foot to eradicate with pesticides.
An embankment behind an alleyway next to the homes of Mr Metcalfe and neighbours is riddled with the weed, some of which has grown to around 10ft already.
Mr Metcalfe, an NHS support worker, has been left devastated after the collapse of his house sale.

An embankment behind an alleyway next to the homes of Mr Metcalfe and neighbours is riddled with the weed, some of which has grown to around 10ft already. He is unable to cut back the weed himself for fear he could be prosecuted for damaging property

He and other locals have long complained about the potential danger the weed poses to the foundations of nearby homes on his street, in the town of Edgeley.
He is unable to cut back the weed himself for fear he could be prosecuted for damaging property.
Mr Metcalfe said: 'We had fallen in love with a house and put an offer in but our sale fell through and we were left stranded.
'Japanese knotweed isn’t something people know a lot about but it can cause a lot of problems.

More...

• Celebrities besieged by 'Triffids' superweed: Homes of Thierry Henry, Tom Conti and Melanie Sykes under threat from invader
• Splashing out on your garden can add tens of thousands of pounds to your home's value, claim estate agents

'We had been planning to move for two or three years so to have it fall through was frustrating.
'It is clearly a real problem when someone can’t get a mortgage because of weeds. I was told that if it didn’t get sorted out then I would have to sell at auction, or find a cash buyer, because it would be impossible to get a mortgage.

'When the survey came back, not only did it show up the knotweed as a problem, it also said that for the sale to proceed there would have to be a full "migration plan" put together to chart where the plant was and how it was travelling.
'Of course, the buyer got cold feet because it sound like such a complex problem.
'As soon as you start reading a few articles about knotweed, you realise that there are a lot of mortgage lenders that simply won’t offer a mortgage on a home that has knotweed nearby.
'We feel like we were left completely stuck in this position while we wait for the knotweed to be treated.

After contacting the local council property management company, NPS, it has agreed to treat the knotweed - for the first time in two years - and will give Mr Metcalfe a certificate guaranteeing it will be kept in check for five years

'The council are now working to sort the problem out and we just have to hope that we can find a buyer that is open minded.
'In a way, we were lucky that it was on council land because the situation is now getting resolved. If it was private land, I would be in a much more serious situation.'
After contacting the local council property management company, NPS, it has agreed to treat the knotweed - for the first time in two years - and will give Mr Metcalfe a certificate guaranteeing it will be kept in check for five years.
Local Labour councillor Philip Harding, who raised Mr Metcalfe’s case with Stockport Council, said: 'It has been a problem there for 10 years so I don’t know why it has taken so long to deal with properly.
'I am pleased this is going to be sorted out but it should have been done much sooner.'
Japanese knotweed, native to eastern Asia, grows rapidly and is strong enough to damage concrete.
Liberal Democrat councillor Mark Weldon, executive member for Stockport community services, said: 'We are committed to tackling this issue and have a comprehensive policy to address Japanese knotweed.
'We are aware of the residents’ concerns and contact has been made with them.
'This site was treated for Japanese knotweed a couple of years ago when it was brought to our attention.
'There has recently been some re-growth which will be revisited to treat.'

THE DEADLY INVADER... AND HOW TO TACKLE IT

The curse of Japanese knotweed

Japanese knotweed – which has the scientific name fallopia japonica – was introduced into Britain by the Victorians in 1840.

Incredibly invasive, it can grow 4in a day from April to October and a tiny root can establish itself as a plant in  just ten days.

Apparently solid structures such as tarmac and flooring in houses are no barrier to its growth and the weed also creates a risk of flooding if leaves clog waterways.
About £1.6billion is spent a year in an attempt to remove it.
Knotweed is recognised by its shovel-shaped leaves, bamboo-like stem and white flowers produced in autumn.

If you discover the plant on your property, these are some of the steps you should take to prevent further problems:

• Immediately create a 21ft exclusion zone around the suspect plant.
• Do an initial spray with glyphosate-based weed killer.
• Do not excavate or move soil from the exclusion zone without instruction from the local authority.
• Cutting should be done with sharp secateurs or pull it out by hand to avoid dispersal of fragments.
• Wash feet and clean shoes when leaving the contaminated area.
• If you cut down knotweed, you can burn it on site or bury it – 16ft deep, covered with a root-barrier membrane and with inert topsoil – with permission from the Environment Agency. Material taken from the site must be disposed of at a licensed facility.