[Fluffball]

The amount of risks associated with outdoor housing vastly outweigh any potential excuse. More space is no reason to house a cavy outdoors, subjecting them to temperture fluctuations, predators, weather extremes, illness, drafts, insects/parasites e.t.c An indoor housing situation can easily be changed to provide more space. Moving around furniture, building a top level, providing more floor time, modifying their cage. I know many owners who live in tiny one bedroom apartments and still manage to provide the minimum size requirements as stated on cavy cages.

Even if that animal has a a limited or certain amount of interaction with its owner it is not constant. As mentioned earlier:

Social interaction may only occur during feeding times or at certain times of the day if they are housed outdoors. Cavies need social interaction 24/7 even if it is not direct. They must be able to see, hear, smell and be present in all family activities, even if it is from the safety of their cage. They must be part of the family. Depriving a guinea pig of this interaction is not valuing it as a member of your family or as a valued companion. Keeping a guinea pig isolated from household life even if it is only for short periods of time during the day is not ideal. They must have a permanent presence in the household to be able to effectively benefit not only socially but psychologically as well.