How can he stay in own home?

can he get a bank loan using the hose as security?

He'll probably have to sell and rent somewhere. Getting divorced in your later years, nobody wins unfortunately. It wouldn't be useful to take a mortgage when he is only getting the aged pension. At this stage of his life, better to rent a small one-bedroom place.

Has he applied for a mortgage? Mortgage companies are allowing short term mortgages - 20 years or so. £40k is not a lot to borrow by today’s prices, and may work out cheaper than rental.

www.theguardian.com/money/2018/may/19/mortgage-99-years-old-aldermore-bank-mature-borrowers-home-loan-later-life

That's not true about knotweed. A) it doesn't need to cost so much to eradicate £10k ! You're joking. I'll come and do it for less. But perhaps that's just the valuation.
B) unless a neighbour's house has been undermined, it isn't considered the evil it used to be!
It is a difficult situation for your friend. So often its the woman who is in that situation and has to remain in an unhappy marriage to keep a roof over her head.
Times have changed and there is equality in all things now

Unfortunately, I fear the only solution may be to sell up. But He needs to talk to a financial adviser. They have a wealth of knowledge about ways to raise, invest and look after money.
I know my sister was keen to divorce years ago until she discovered that all she would be entitled to was half of their debts.

Try John Charcol, mortgage brokers. They just re-mortaged our buy to let's, I'm 71 and DH is 81.

Dear me, what a time of life to get divorced. Can't they live in separate parts of the house and just ignore each other ? Seems a bit drastic to have this sort of thing hanging over anyone at that age. If the worry of it all doesn't kill him, a move to strange surroundings could.
Moving house etc at any age is said to be the highest in the stress stakes.

Your friend will need to determine what his priorities are. If he must keep the house at all costs he will have to maximise its income earning potential by letting out bedrooms, put the front drive as a paid for parking space on parapedia etc.

He may find when he things about it he has other priorities and is glad to take his share an move to a more suitable accommodation.

He needs to take at least some legal advice. The options and the time frame may not be as black and white as his wife would like him to think. CAB offers free advice on this.

we have just done equity release, over 80, so didn`t affect our benefits.

I cannot recall them asking about our income, well not to say that it affected our application.

perhaps, if he really wants to stay in the house, he tries another company that does Equity Release.

Supported housing would probably accommodate him if there are such places in the area. It's still an independent way of living and rents are nominal. Meantime he could have his home on the market and then enjoy his share of the proceeds while remaining safe and secure to come and go as he likes with the option of a support officer to call on a specific day.
I'd be doing that if I were him if he's being pressurised into parting with cash, though a house doesn't sell overnight------but he can put his name down for secure housing when the time comes.

Equity release is one answer, no income status is required and the money released is returned when dies or goes into nursing home due to requirements.
Or, sell up and look into a flat or cottage (depending on money left after settlement) in a retirement village/complex where there are other like minded and aged people to meet.
Get good advice and a good solicitor, he may not have to pay out the full 50% if she did not contribute to house purchase costs over the years.
A horrid situation to be in, but not the worst if looked at carefully. Good luck.

The Telegraph had an article on Japanese knotweed and the incorrect information affecting property valuations. It was May 16th and you can look at it on line so maybe your friend could show this to a financial advisor when he sees one. Is it possible for them to convert the house into 2 independent homes ? If they can't bear to be that close to each other maybe his wife could use the income from a tennant to help with her rental costs, of course, she would need to pay half of the conversion cost so perhaps this isn't possible.

You say his wife wants just under half the value of the house but it's not for her to decide but the judge in the divorce case (if they go to court).

Most building societies don't like to lend money beyond 75yrs old. So he would be able to borrow for 4yrs? I was told Nationwide are the best bet for elderly borrowers.

Thank you all for your help. I had a read of the articles and a bit more of a hunt around, and it seems there are quite a few mortgage companies that now loan to over 70s, and older! The house is too small to rent a room out. In a divorce, it is up to the couple to agree on the split of monies, but of course if they can't then they have to go to court, which would cost far too much.
I will have a look into the knotweed for him as well.
Where he lives now is quite a cheap property, I think a retirement flat will probably be more than his house!
Thanks for your help, and please do comment if you have any other ideas!