Do not plant near buildings, sewers or on clay (due to subsidence problems) they have wide spreading roots.
Eucalyptus are generally planted for the young leaves which are a blue/grey colour and very pretty, sadly though if you do not prune the tree religiously to maintain the young foliage, you quickly end up with a fast growing monster. Eucalyptus can quickly grow to at least 60ft, so maybe not for the average sized garden.
We haven’t used Eucalyptus in any of our small garden designs – but we do use lots of other plants that are much better (we think).
Why don’t you take a look