Boston Ivy on two-storey house: a few questions

Looking for some guidance on growing Boston Ivy (veitchii variety) on a four-bed two-storey detached house.

I have a few questions:

1. How many plants would I need to buy to cover the house (it's a typical two-bedroom detached house)
2. How many years would the plant need before it (mostly) covers the house?
3. How many times per year does it need to be pruned to prevent it clogging drains and going onto the roof (I don't like heights so I'd need to pay someone to do this)
4. Finally, is there any guidance for prepping a planting hole? Currently the house is surrounded by sturdy concrete footpaths, so I would need to do a job on that for planting.

standardg60

1. one will cover a house eventually but if you want to speed it up maybe 8-10 feet apart.
2. how long is a piece of string. it depends on lots of conditions, aspect, soil, feeding etc.
3. as many times as it grows into said gutters and roof, but once a year should suffice
4. I've cut a 1ft square hole in a concrete driveway, removed the concrete, replaced with a bit of soil, planted said virginia creeper, healthiest plant i've ever seen!