I have mine loose in the dining room for floor time. There are no low sofa/tables or wires - just the computer table that we block off, although they are quite good at breaking in!
To begin with we were worried about having them loose, but they escaped their carry box several times (three little pigs running full pelt at the open door inevitably leads to escapees!) and we saw they didn't get up to too much mischief and always (so far) went back into their pen/carry box to pee, that we now let them run wild for about an hour three times a day. {Mine are only inside at weekends}
Thy do chew the carpet ... And the dining table legs....and the computer table wheels...an the box out mortgage stuff is in ...and almost anything else they can get their teeth on! But they don't chew the floor length curtains, they like playing under/behind them!