If you are a programmer with kids who writes code at home, can you please say what times of day/week do you write code, and for about how many hours a week.
Now, though, I got an office a few miles away from home. It costs more than my mortgage but it has paid dividends. I still work at night but my daughter is now a solid sleeper (tempting fate there..!) and my wife is OK to get up with her in the morning. Having an office without any worries of childcare is working out marvellously and it's more than paying for itself.
If you plan carefully, you can be very productive - try something like the pomodoro technique to make sure you aren't just faffing about. Evenings after work I found it better just to enjoy time with my family and get some exercise and rest.
Since I do have a day job, I try to come home and spend solid time with my wife and kid before she goes to bed. After that, I do my best to claim it as alone time. The wife is really understanding, which really helps.