How old is the house, does the brickwork look sound, wisterias are not self clinging like say ivy, they are twiners hence the wire framework. There is always a possibility of any shrub/tree roots entering underground pipes, usually old pipes that are already cracked, which is why I asked how old the property is. Again, problems with foundations are something to think about if the building perhaps over 100yrs old, or you are in an area where subsidence is likely. Lots of people have wisterias on house walls, I dont think its normally a problem.
Hi Pete, It is around 20 years old. Do the roots usually not like going for concrete etc and will just go the other way? Do you know how the roots spread are they down or horizontally and near the surface? Finding the info online a bit contradicting I would have to go look at the brickwork or get the surveyor to do it. Does the weight of them on the wirework usually pull mortar out?
The roots usually are looking for water so would tend to grow away from the building, I dont think wisteria if particularly deep rooted, I dug one out some years ago and it never reappeared, they dont tend to sucker IMO. As to damage that the wires might do to the brickwork that depends on how it was fixed and obviously a maintenance thing that would need to be checked on. I wouldn't think it could cause any real structural damage unless the brickwork was substandard to start with.
Agree with @pete as modern houses are built to higher foundations standards than older ones eg pre 1950s. If its the property you really want, you could ask your solicitor to make the purchase conditional that the vendors , if they agree, remove the plant, make good any upper wall defects from the wiring system and provide photos or independant report etc to show the root system has not affected the foundations.
I didn’t know, but different types of wisteria present different degrees of problems. See here Wisteria in the kitchen! - Environment Controls I did once see a very old and extremely muscular wisteria which had pulled a very expensive balcony off a million pound ( forty years ago) house in Richmond Park.
You might reduce your offer to reflect the potential risk of future expenditure in removal/repair. Do you like the plant in that position ?
Personally I'd say it the building that is not up to scratch if you get it coming indoors they obviously have a damp problem anyway. Balconies are presumably built to take a certain weight, if you over stress them I could see it being a problem, bit like leaning a full grown oak tree up against your house and wondering why the house fell down.
As far as I know no, but there are different ways of growing wisteria, some people train them up the house or over an pergola, others grow them as a more column like form which may look like a tree. If it grows between say the house and a balcony then as the wisteria grows the balcony will be forced away from the house answer is look after the wisteria properly. My brother has a wisteria that he has trained around two sides of his house (100+years old) the house has rendered walls and the wisteria as in your case is trained on wires. The render has suffered no damage over the years he does ensure it does not get behind the gutters or under the tiles by keeping it below that height. Wisteria need a wire support that they can wrap tendrils around to climb, unlike ivy which attaches to the wall directly by suckers. This means that air can circulate between the house and wisteria reducing the chance of damp. The house is only 20 years old so probably built on a concrete raft so the wisteria roots will not becoming up through the floor. You are employing a surveyor if they think it is a problem or potential problem they will flag it up, note they tend to be risk averse to avoid clients suing them. As for scare stories search the internet and you will find scare stories about anything and everything, be that wisteria, grass, worms, water, potatoes etc; remember bad news sells newspapers good news doesn't.
No they just get bigger as they get older and are long lived, mostly. The house is only 20 yrs old so it is probably still a youngster.
I think that whether it is an issue is down to a discussion between you and your surveyor. I would take their advice. Also do you particularly want a wisteria on the house as it will require some attention re pruning a couple of times a year. This link How to grow wisteria / RHS Gardening will give useful advice about looking after a wisteria.