I would have said Magnolia campbellii type, although if it's in flower now, it's a little late, they're spring flowering. Phil J

It's 'Felix Jury', sometimes incorrectly called 'Felix', and, rather prosaically soon to be re-named as 'Jurmag2' (as in Jury's Magnolia number 2) a fairly recent New Zealand hybrid.

Looks pretty spectacular!

thanks to all. The magnolia was in flower in spring, not now. If it's Felix Jury then I am delighted as I lived 40km from the Jury's and often visited their garden and nursery!