Looks like an Empress Tree, Aka Royal Paulownia. Paul is the first name of one of my sons so that how I remember that one. Let's see if my guess is good from what the other members have to say.

It does rather, but I thought Paulownia had purple flowers? At least ours does.

100% not Paulownia...they have lilac flowers and much bigger leaves. Not sure what the tree is...it looks like an Exochordia but never seen them as trees. Amelanchier maybe ?

Whatever it is, i want one!!!!

Could be a lot of things, from white lilac (unlikely, you'd have mentioned scent) to a fancy variety of Prunus padus. Is it fragrant? Does it have berries later in the year, and what colour are they if it does? What's the bark like? What part of the world is this growing in, and is the tree in flower right now? If it is, a close up of the flowers and also the leaves (can't tell if they're toothed or not in the pics you've posted) would be good for detail.

Lovely whatever it is, but not Amelanchier and not Exorchordia, sorry :(

I was thinking prunus padus waterii there is one near me too :)

It certainly smacks of a Prunus padus variety to me, Daylily...

Hi, another vote for Prunus padus 'waterii', Derek.

My dad showed me this tree a couple of years ago just a few streets away, I identified it in a book I have, its lovely, as you say it could be a different variety, Bamboo :)

Thanks to everyone who answered my question! :-))

It would appear from the photos on Wikipedia that this is indeed Prunus padus 'waterii' or 'Hackberry' or 'Bird Cherry'. It also seems it does have a slight scent but it never occurred to me at the moment of taking the photo to take a sniff! LOL!