Japanese Knotweed

SouthLondonUser

Because you can't always find an identical property without the knotweed, so, if you like the one with, it may make sense?
Because if an entire area has a history of knotweed, the odds it will spread to the houses 100 yards away are not low, so buying there doesn't guarantee much?
Because maybe the threat is overblown? https://www.irishtimes.com/news/ireland/irish-news/irish-ecologist-says-threat-posed-by-japanese-knotweed-vastly-overstated-1.3579973

GDB2222

If the entire area is infested with JKW, then I suppose it's priced into all the properties? I don't know whether it produces seeds and they get blown all over?

SouthLondonUser

The areas I know of are the typical rows of Victorian terraced houses. Where there is an infestation which affects two "half" roads, say the northern half of two roads whose houses have neighbouring back gardens, I have seen basically the same prices in the parts with the infestation, in the parts of the same roads with no infestation, and in the next roads with no infestation.
I also know of 3 people who have sold in the area with no issues, and of 5 properties that sold over the 18 months before covid, all relatively quickly.
It is of course not a scientific assessment that can be expected to be representative nationwide.

I would have expected houses with knotweed to be something like houses overlooking railway tracks, where you can very clearly tell they cost less and take longer to sell, but it's not what I have seen here.

Again, I am not saying the OP should ignore it, but that he should do his homework; if the same happened in the area he wants to buy, I wouldn't be worried. Of course I am sure there will be areas where maybe it's not widespread and buyers freak out.

Jba1988

The surveyor said that the knotweed was within 3 metres of the house. The treatment company which have since been out have said the infestation is roughly 24 sq m, and are treating the whole infestation even where it goes onto neighbouring property (the land isn't useable as a garden, so no fence dividing from the house next door. I'm hoping to hear back from mortgage lender tomorrow.
I didn't realise buying a house was going to be so difficult - this is the 3rd I've tried to buy. Apparently I'm not good at picking them!

SouthLondonUser

OP, has the treatment already been paid for? How many homeowners are affected, just you and 1 neighbour or more?
If all the affected neighbours have got together and paid for some kind of communal treatment it's a very good sign.
If one of the neighbours is uncooperative it can be a big issue because you will never get rid of it.

Have you tried knocking on the neighbour's door to explain your situation and have a quick chat about this?

elsien

Jba1988 said:

The surveyor said that the knotweed was within 3 metres of the house. The treatment company which have since been out have said the infestation is roughly 24 sq m, and are treating the whole infestation even where it goes onto neighbouring property (the land isn't useable as a garden, so no fence dividing from the house next door. I'm hoping to hear back from mortgage lender tomorrow.
I didn't realise buying a house was going to be so difficult - this is the 3rd I've tried to buy. Apparently I'm not good at picking them!

When are they treating it? If they're doing it now it's too early in the year. They need to be either injecting into the stems or spraying at intervals in August/September when the plant is due to die back anyway and will take the chemicals back down into the rhizomes. When are they next planning on coming back - I'd be checking their treatment plan quite carefully if I were you. 

daivid

OP I would start looking for other properties. Not because Japanese Knotweed is the end of the world but because your lender may withdraw the offer. If the lender is still willing to lend then I wouldn't necessarily be put off. JK is in almost every part of the UK now, if you have a railway line or watercourse nearby there is a good chance you have JK near. The fact it has been identified may be a blessing in disguise as you and the neighbours are aware and will hopefully now be careful to look out for and deal with any further infestations. Which leads to what would be my greatest concern - would the all the owners of surrounding properties be diligent in dealing with JK? There is JK within 1/2 a mile of my house in at least 3 different locations, but as I am surrounded by homeowners who care for their houses and gardens I'm not overly concerned. If I shared a boundary with Network rail, a rented property or a derelict property I would be more concerned.

hazyjo

GDB2222 said:
Each side had an expert valuer to advise the court on the effect of JKW on the house value. One said a 3% reduction and the other said 23%. The case was settled out of court, so we'll never know what a judge would have decided - probably halfway in between the two figures. 

Actually, it was reported as "The expert for the claimant put the figure at 23% of the property's value, whereas the expert for the defendants came to the more realistic figure of 3%."

And that was after they'd bought -presumably their argument was they'd not have done so. You're already aware!

I think 25% is crazy, you don't. No point in trying to establish who's right. So good luck, do let us know how you get on if you re-offer. I know what I'd be telling you

Jba1988

elsien said:

When are they treating it? If they're doing it now it's too early in the year. They need to be either injecting into the stems or spraying at intervals in August/September when the plant is due to die back anyway and will take the chemicals back down into the rhizomes. When are they next planning on coming back - I'd be checking their treatment plan quite carefully if I were you. 

They did the first treatment a week or so ago, and then the next treatment is around August September. I believe the plan is to spray it twice a year, then come back and do a clearance in the winter for the next 4 years.

daivid said:

OP I would start looking for other properties. Not because Japanese Knotweed is the end of the world but because your lender may withdraw the offer. If the lender is still willing to lend then I wouldn't necessarily be put off. 

I've decided it this one doesn't happen then I'm going to rent for a bit. Now doesn't seem the time for starting another purchase - uncertain what prices are going to do, and 90% LTV mortgage deals seem pretty poor compared to what they were a couple of months ago. I have my deposit and keen to get out of my parents! In a way mortgage offer being removed is good, as I don't need to make a decision.

hazyjo said:

I think 25% is crazy, you don't. No point in trying to establish who's right. So good luck, do let us know how you get on if you re-offer. I know what I'd be telling you

I didn't say 25% - I'm thinking about 10% seems more realistic from the figures I have seen online. What ever happens got to work financially for both parties, if we can't find something that works for each of us then it is what it is.

GDB2222

hazyjo said:

GDB2222 said:
Each side had an expert valuer to advise the court on the effect of JKW on the house value. One said a 3% reduction and the other said 23%. The case was settled out of court, so we'll never know what a judge would have decided - probably halfway in between the two figures. 

Actually, it was reported as "The expert for the claimant put the figure at 23% of the property's value, whereas the expert for the defendants came to the more realistic figure of 3%."

And that was after they'd bought -presumably their argument was they'd not have done so. You're already aware!

I think 25% is crazy, you don't. No point in trying to establish who's right. So good luck, do let us know how you get on if you re-offer. I know what I'd be telling you

Two valuers differed by over 20%, so I’m sure we won’t agree. Nor, as you say, do we need to.  The comment about realistic figures was not from a valuer, so nit really helpful.

To the OP, I suggest you Google Japanese Knotweed Valuation. That gives an interesting range of answers.