Knotweed - more than 7m and with treatment plan

[NervousBuyer2021]

So. Having walked away from one house after a bad survey (and seller not willing to work with us to deal with any of the issues) we’ve found what is the perfect house for us, in the perfect location for us...with a small patch of knotweed at the back of the garden.

It’s more than 7m from the house, there is also a small bit in a neighbour’s garden and the seller has already started treatment with herbicide through an approved contractor.

We’ve spoken to the contractor doing the treatment and he’s been very reassuring. He has looked in all neighbouring properties and only found it in two, both being treated and they’ll continue to survey neighbouring gardens and ours for 5 years.

We want to go back and ask him if a quicker (and maybe more effective?) treatment is possible, some kind of excavation. That would give us full use of the garden much quicker as otherwise the treatment takes up to 5 years. We’ll still have plenty of garden but will have to fence off the knotweed bit to make sure it’s not disturbed and able to spread as a result while the herbicide treatment is ongoing.

Wondering if anyone has been through the herbicide treatment programme and had success?

Also wondering if we are naive to think that this all sounds reasonable...we know it’s not ideal but it seems to be possible to sort?

Right - an update. We went for a second look today and the knotweed isn’t fenced off at all, which it should be according to the treatment plan. Otherwise it can spread by people walking on the soil and then on the rest of the garden, or kids pulling at the plant or whatever. We assume lots of people have been through the garden having viewings.

So on that basis we think the only option would be to excavate / dig and dump the garden basically. What do you think the chances of getting the seller to pay for that might be...on the basis that they haven’t managed the issue properly?

The fact this issue hasn’t and isn’t currently being treated properly would hugely be a big red flag for me. If you need a mortgage I’m assuming this is going to pose a problem as well if not being correctly treated.

It’s rather negative that an approved contractor isn’t working with the relevant parties to get the respective area correctly fenced off, or whether the property owner indeed is ignoring the instructions to do so.
If they can’t organise simple fencing off of the area it seems improbable that they would agree to your suggestion. However, this situation will arise with whoever they try and sell to but you may be more vigilant in investigating the ongoing situation.

Excavating is very very likely to spread the knotweed, not to get rid of it. It’s also likely to be eye-watering my expensive. It’s be a huge volume of soil to remove. And then your garden would have no decent topsoil.

It’s pretty unlikely that anyone has been walking through it or pulling it up and using it for sword-fights during viewings. Personally I think the home owner is a fool not to just have fenced it off, but people do dumb things

We have knotweed at work. We only use organic stuff, so can’t treat with herbicide (I don’t agree with this policy when it comes to knotweed, but...). In the 10 years we’ve been there, it’s not spread at all - the area covered has actually shrunk and all we do is cut it back to ground level a few times over the spring - autumn. I know this doesn’t tally with what people online will tell you. But certainly on our clay soil it really genuinely isn’t the concrete-destroying nightmare claimed.

I’d not find it a deal breaker so long as (a) I could still mortgage, (b) I was intending to stay for 5 years minimum, (c) neighbours were treating at the same time. (d) I could afford the treatment cost. You’ll be paying marginally less due to the knotweed, which is an entirely solvable problem.

Okay that is a really helpful perspective to have in the mix actually, thank you!

Although wondering why excavating would be likely to spread it?

Also just for context the seller is a builder who has been doing the house up over the past year so I am more concerned than I might be about how careful they’ve been in the garden.

Why would you make their personal financial disaster into your own financial disaster? You're effectively proposing to underwrite their losses to the tune of hundreds of thousands of pounds by taking this house off their hands and giving them a lot of money for it. They aren't even treating the knotweed properly, you can see this with your own eyes, goodness knows what you haven't yet seen.

If you're having 2nd thoughts during a loopy housing bull market, how saleable will this house be if you need to sell during a quieter, more normal market?

This information is a gift. Take that gift and walk away.

Agree with @PicinRed
Why would you want to move into a house where you have to live with a monster in your garden that you have to worry about for years.

Run

I suppose we are trying to work out to what extent it’s a monster - if it is treatable and we can get this otherwise lovely house to live in, it seems worth considering which is what we’re doing.

Appreciate the perspectives for sure.

There have been more recent reports this year that have actually said knotweed is less evasive than originally thought and that bamboo is equally as bad around properties. I certainly wouldn’t be cutting your nose off to spite your face, there are lots of ways to deal with this.

Knotweed is treatable and herbicide is the easiest method. I wouldn't worry too much about the fencing off if it's a small patch and it's not on a walkway or in the corner of the garden.

With regards to dig and dump it can be very expensive. You'll have to get the soil tested and then you'll need a licenced landfill (there aren't too many around) and licensed removal company to take the soil.

Another quick option if it's a small patch is to herbicide treat first then dig up and sift out the rhizomes by hand and burn on site.

NervousBuyer2021

I suppose we are trying to work out to what extent it’s a monster - if it is treatable and we can get this otherwise lovely house to live in, it seems worth considering which is what we’re doing

Why. There are and will be other houses for sale without having to think about an invasive plant that is going to impact your life for years and will have to be declared when you sell the place.

As WowIlikereallyhateyou said, bamboo is an absolute nightmare to get rid of.

There's lots ways to treat knotweed and the RICS rules are set to change / ease soon with regards to it on residential properties.

In answer to why we are under time pressure as we don’t want to lose our buyer and there aren’t lots of other houses in the area we want to live in that we can afford. If one came up we’d consider it, of course!

Thanks everyone for the advice and perspectives. Lots to think about.

Getting a mortgage may get more difficult due to the knotweed. May also make reselling more difficult, I’d guess. Personally this would be a dealbreaker for me.

As others have intimated, it's the mortgage lender's perspective that matters here. Find out your bank's policy, ASAP. Ours requires a guaranteed, insurance-backed 5 year treatment plan to be in place. Without that you may not be able to raise a mortgage on the property at all.

We fell in love with a house with knotweed. Our mortgage provide pr valued the house at £0.00. Because the problem wasn’t controlled.

The problem you have is manifold. If the knotweed is next door too, who knows who started the problem? If it spreads TO them or another neighbour from your house, I believe you are liable for that. If you treat your problem and they don’t and it returns from their side, they are liable. But do you really a) want these risks b) want the arguments with the neighbour about cost c) want your entire garden dug down several feet, loads of chemicals being spread around... and you have kids.. in my view it is just awful. These issues can go on for years, even if you have a decent ten year insurance or bond from the company that does the treatment, that they will come back and fix problems if it returns.

Then if you do need to sell in future you have to disclose this. Many people will like me just run a mile from a house like this.

We initially told our seller that we would consider buying the house if they dropped the price by £75k being the cost of potential treatment and the cost of redoing the excavated part of the garden and the unpleasantness of being unable to let our kids play need the area soaked in chemicals. Our seller was furious, but while they were deciding the mortgage company’s valuation just told us everything we need to know.

It is a really awful problem and frankly I wouldn’t go near it unless you are utterly desperate.

Everything that our mortgage provider (and most mortgage providers) need is in place. Although tbc as to whether they agree with the valuation.

Thanks @CustardyCreams

It is on one neighbour’s garden as well and being treated there.

You are insane if you buy this house. You’ll never get rid of knotweed and trying to kill it will bankrupt you. If it spreads it can literally grow through the concrete walls of the house. You will have problems when you come to sell. It’s a monster. Run like the wind!

Honestly I would run away from this house.
Quickly.

• the vendor is basically flipping the house. I don't trust "renovated to sell" houses
• it has knotweed!
• the treatment plan isn't being followed
• time pressure stops people thinking objectively and clearly.
• resale will be a NIGHTMARE. UK buying and selling is hard enough without added layers of stress / problems this brings.

Move into rented if you don’t want to loose your buyer. Buying a house with Japanese knotweed is completely insane.

I wouldn't buy any house where solving a problem relied on the cooperation of neighbours