All other buildings to the east of Portia Way are even numbered, so the error must be way 227869652 which should probably be 2-10 even.

But I'm also puzzled that node/3923656646 claims entrance to 49-63. 

a) There must be an unmapped entrance(s) to 1-15.

b) mapping housenumbers to entrances is good and should be done more often, but then way 227869643 should not duplicate the housenumbers claimed by its entrance.

c) is this the sole entrance to 49-63?