g'day sue,

they can cover to around 2.5 to 3 meters in width, but you can also
trim the outer trunks off to keep them narrower. would leave about 1
to 1.5 meters clearance to fences, again any that threaten damage to
the fence can be removed from the clump. with your front boundry it
shouldn't matter if they encroach onto the footpath a little as in
most cases you are aloowed a garden bed along your front boundary
outside the fence, and fronds and trunks can be kept trimmed or
removed for the comfort of others.

how fast they grow depends on a lot of things least of which is the
medium you plant them in and how much water they get, in a good rich
medium with good watering they will grow quiet fast, keep them well
mulched.

len

snipped
--
happy gardening
'it works for me it could work for you,'

"in the end ya' gotta do what ya' gotta do" but consider others and the environment
http://home.dnet.aunz.com/gardnlen/