SelectASpaniel stays on the floor 95% of the time, but around Bonfire Night and New Year's Eve he is allowed up next to one / inbetween both of us as fireworks make him nervous and lying beside us calms him down. We use a large bath sheet to cover the sofa before inviting him up, which is easily washable, protects the seat from getting too hairy and can be quickly removed in the event of visitors.
But then I'm considered slightly odd by some anthropomorphic weirdos animal lovers because the dog stays predominantly on the floor, isn't allowed upstairs - as much because stairs are very hard on dogs' joints and SAS has arthritis as any other reason, admittedly - isn't allowed to lick plates, the cat isn't allowed on kitchen work surfaces or the dining table or my bedroom at night (that's when my asthma is at its worst) or in the spare room if we have guests. I love them to bits, they're house pets and they have plenty of comfy places to sleep, I talk to them all the time - but they are animals, and are treated as such, not as small furry humans.