However far you plant it from the house will not prevent the roots reaching your foundations. So you plant it far enough from the wall that the stem and major structural roots will be able to expand without hitting the wall. Two or three feet is plenty. Sounds a lot but remember you are planting something that will be like a small tree eventually.

As to whether you want the roots under your foundations isn't something I can really answer. I don't know what type of foundations you have. A simple concrete pad? How thick? What is it sitting on? One of the most common problems with foundations isn't physical damage from roots lifting the pad (a concrete pad to modern regs is far too strong for that) but is settling caused by clay shrinkage in a drought. Thirsty trees, or wisteria, can contribute to that shrinkage, but then a big maple twenty or thirty feet away will be a bigger threat than a wisteria right up against the wall.

Remember that wisteria won't climb a wall, you'll have to tie it onto supports like bolts or wires.

Many thanks for your helpful advice. I will bear it in mind when planting my wisteria. The house is an old small victorian one with not much underneath. I think the walls just sit on the London clay.Perhaps this could lead to shrinkage if the roots grow underneath.