We are thinking of getting a Buhund. Friends already have two. We work fulltime and the dog would be left on its own for approx 9 hours - would this cause the animal too much distress or would it be okay. Our friends dogs are okay if left for long periods.

Well, I wouldn't sell you one. Buhunds were bred to be active working dogs, they also love company & are very intelligent. It isn't fair to leave any puppy 9 hours a day - and almost impossible to train, particularly housetrain it.
They will cope if left for long periods occasionally, or even once or twice a week, but to leave a dog all day 5 days out of 7 is just not fair. If Buhunds are bored - and they certainly would be left for that amount of time - they will be destructive and/or bark ...and bark .... and bark.

Don't bother luv.
Both me and my husband work but i make sure i am on the oposite shift to him or i turn it down. Our three are never left alone for more then 2 hours, no longer than a shopping trip or out to lunch. 9 hours, good lord they'd go insane sitting around bored all that time. As for toilet trips, it would have to be the floor for a puppy left that long, no puppy can hold it that long!
So......
a puppy or adult dog owned by you would basically live alone for 80% of its life, sit in a room full of its own pee and whatever else and have no manners as you wouldn't have the time to train it.
I would leave it until you are in a position where you can offer a dog company for the majority of the day, take it out, train it and be a part of its life.
I know i sound as though i'm b****ing again but thats how i see it. Sorry for any offence caused.