Looks like a Deutzia although which one I don't know :-)

It's a Mock Orange, or Philadelphus

Agree with Mucky fingers

I reckon deutzia too, philadelphus has single flowers except for virginal, the leaves are similar though

Both Deutzia and Philadelphus are related and belong to the family Hydrangeaceae. They also look very similar, and both have double flower varieties. However, the Philadelphus flowers have a lovely citrus perfume that the Deutzia lacks. So, does it have a perfume? ;-)

Deutzia for me

Deutzia.

Deutzia.

Deutzia, most likely D. scabra flora plena

I have a small Deutzia growing & looks just like your flowers, they have just finish & dying off now. I also have two Mock Orange Shrubs, they are not in flower yet so Deutzie is the more likely shrub. ?
I must say it is a lovely specimen :o))