Note that any fast-growing shrubs will need frequent trimming--and, so, will be high maintenance. Dwarf forms of columnar Junipers ('Robusta Green', 'Blue Point'), dwarf forms of Cherry Laurel ('Otto Luyken', et al.), and semi-dwarf Oriental Arborvitae (Platycladus orientalis varieties), are low maintenance, but will take several years to reach the required height. Putting up a tall trellis with vines will be faster, but may violate more council rules, and will be almost as expensive as a tall fence.