I live with my boyfriend in London. We both have full time 9-5 jobs and REALLY want a dog. We've discussed what breeds we like at length and agree 100%.
Only trouble is our landlord isn't keen - I assume this is because the flat we're in is furnished by her and she doesn't want any scratches or nibbles on her furniture, which is fair enough.
My office allows employees to bring their dogs in, a few people do and everyone is happy with it. My boyfriend will almost definitely be moving offices to a co-working space that allows dogs this year. We're total homebodies so the dog would never be left at home unattended for more than an hour, we would take it basically everywhere we went aside from the occasional nip to the shop or short meal out.
We both have experience with dogs and puppies - albeit from childhood/teenhood but still.
My boyfriend does all the communicating with our landlord and I've never actually spoken to her more than saying hello, so I don't feel that I can just step in and email or call her out of the blue. He refuses to ask out of awkwardness/politeness. I'm happy to chip in more money towards rent if that's what it would take to persuade the her.
AIBU if I just... buy a dog? You know what they say, it's easier to apologise than to get permission. 
I'm not even suggesting we would be dishonest about it, I just feel like it would be much easier to bargain with her when she sees the sweet little cockapoo we've got isn't a bookcase destroying monster. I know it's not the best thing to do but so many other people seem to get away with it.