,Hi, I hope someone here might be able to suggest a replacement for my Plumeria tree that is in my front garden. The tree is about 20 foot tall and whilst attractive i would like something different and also a tree that is not shedding leaves and flowers constantly.

So if anyone can suggest an attractive tree that does not need much maintenance and does not grow much larger than the present one i would appreciate it

Consider a palm. A smaller, ornamental variety, Kentia, Chamaedorea or Phoenix roebelenii (pigmy date palm). 

 

It's hard to find a flowering tree or large shrub that doesn't produce some nuisance leaf drop, flower or seed litter. 

 

Either that or change your mind.  It's hard for me to imagine sacrificing one of the most desirable fragrant flowering plants in the world to avoid a little clean up meditation opportunity each day. Or give the wife or kid a chore, or hire a gardener. 

 

The plumeria can perhaps be gradually reduced in height by drop-crotch pruning technique, to fill out at a lower height. With the right soil fertility and water management I've been able to build resistance to disease and prevent rust fungus and excessive leaf drop. Flowers, I leave lay, or if necessary gather them up and get high on the intoxicating fragrance before spreading as mulch or composting them. 

Pretty much any flowering tree will shed leaves and flowers to a greater or lesser extent. A large Plumeria like yours is beautiful. You could try a Clitoria Racemosa if you really want a change but it sheds leaves and flowers, as well.