How much space for two backyard chickens in the city ? roommates disagree

So I let the chicken wander in the whole garden for most of the summer (instead of keeping her in her 5m2 enclosure). She of course kinda destroyed the plants, although I'm pretty sure a lot is also due to our garden getting basically no sun. We finally got a second chicken, but my roommates are currently mad that the garden has patches with no grass, and say we should keep both of the chickens in their enclosure with only two hours of outside time per day. I feel like that's definitely not enough and would rather let the chickens wander freely lol, but maybe i'm mistaken about how much space they actually need lol. Another option could be to double the size of the enclosure, making it 10m2. Does that seem like enough space ? Is 2hours per day enough time outside of that ? I'd love any advice, sources online all say different things :,)