Distance from buildings
If you want to allow them to grow to a tree, plant away from buildings and ENSURE THERE IS NO OVERHEAD SHADE. They should be at least two thirds the potential mature height away from a building (more on clay soils) unless they are to be coppiced regularly which restricts the root growth. Eucalyptus roots are not as aggressive as poplar roots, but root growth is very rapid. They are mainly shallow rooting depending on soil type and rainfall. About 90% of the roots are concentrated in the top 12 inches of soil. For maximum growth it is absolutely essential to keep the plant free of weed competition, particularly grass root competition for at least the first two years. This point cannot be over- emphasised.