Do you use one?

Our townhouse is possibly the worst home for a baby ever. It has three floors, all have railings that overlook the floor below it. The best way we could "baby proof" was to purchase a giant circular baby gate and let DS safely play in that during the day.
I feel like he's in baby jail and I know soon he's going to want a bigger space but there's no way, other than building walls - and we rent, to safely let him have free roam.

We are currently looking to purchase a home, just haven't found one yet.
Ugh.

DS goes out with DH to the park and to run errands all the time but sometimes I get sad that we don't have a lot of space for him.
Anyone else living in a small space? Any suggestions?