Under the Public health act 1925 all houses must have a number regardless of whether they also have a name, apart from some exceptions where there is no sequence of numbered properties then names only are allowed. In a lot of cases asking for a house number and only receiving the name is pure snobbery.
used to get a lot of that when i was a cabbie
without a number you would be looking at every house in the road
"oh we dont have a number its called tree tops"
" you do, and when you tell me what is is, we will send a cab to you "
LOL they quickly remembered.