Unfortunately, this is one of those plants which benefits from training and pruning in its first and second years, all of which is done around late April, or after risk of frost is gone. This plant is not entirely hardy - listed as H2, which means it doesn't like temperatures below 5 deg C and is very much at risk if it gets colder than that. Which also means now is absolutely not the time to prune it. You may have to risk taking some off to avoid its blocking light or the pavement though, and reckon on giving it a good prune next year in late spring.

Hi, thanks for replying bamboo. I'm in a bit of a quandry as I think the tree is too close to the house and I'm worried about the roots damaging the house foundations. If I was to cut the tree right back and reform as a shrub next Spring will the root growth be as strong as it would be if left as a tree?

If you want it as a shrub, then in April next year, or after frosts are more or less gone, cut all the shoots to just below the height you want. The following year, remove all stems, leaving just 4 strong, well shaped ones, and cut those back to where you want them. The third year, remove any branches which are long and straggly, dragging on the ground, or sticking into the street. Thereafter, keep it pruned in April yearly.

I hope it's not more than 2 years since you planted it - more mature specimens of the this plant resent having their old wood cut off, though they usually recover because they put out lots of suckers. Which is likely what will occur whenever you prune it back anyway.

As for restricting the roots, well, they will be more restricted if you keep it smaller, but its very hard to predict quite where they'll go and how far - depends on local conditions such as dryness of ground, where the most moisture is to be found, etc. Basically, it seems like this is a case of 'wrong plant, wrong place' - it might have been better to choose something smaller for that area.