What I can suggest (for your sanity and social life): - Pick the weekends (one or two days) where you code for 5-6 hours. - Do it during your work day. If you want something out of your side project, just don't work hard enough at work so you have ressources left for yourself - Ask your boss for a 25 hours working week or try to get one day off without salary reductation to see if you be as productive as before. If not, ask for 10% less.
Divide your side project in learning and developing.
Get a book which you can read during your commune, or even an ebook which you can read during work.And then, at home, take a weekend/one day off/two nights off to develop and code.
I also suggest the Lean StartUp method, which is not only helpful for StartUps, but also for side projects. The key is to develop in small iteration to always have a finish product you can test.
So, don't do everything, pick one little feature, develop it and see where it goes from there.