I recently discovered the term "functional play." I have 6.5 year old b/g twins. Neither are that great at playing by themselves. Used to be the boy could self-entertain with anything around the house. Now he can't. She can at least do pretend play by herself with dolls. They used to pretend play a lot together and now not so much. When they do, it can last for hours. But they are playing together. I've been trying to figure out how to help my son. There doesn't seem to be anything we have that interest him other than a new Lego set to build (which he can do the 18+ ones within one day) We've known he's got an engineer's mind since day one. He doesn't like to play with cars, figurines or anything like that. He just wants to build or figure things out. But we only have so much space and money to foster that kind of thing. Keeping this short. We've already had a lot but in the off chance someone has some suggestions of contained self-play ideas for functional play? Ideas?
ETA: Forgot to add the self-entertain part is backyard and indoor access only. The times when I need to do grown up home things and cannot have them out front unsupervised.