I feel your pain I really do. All of mine wake each other up at night. I haven't slep a night in 3 years. It is awful. Kids need space. All of this is so bad for the children. I suppose when he is not at work, your dh just wants to relax. Maybe hire someone else to do the work on the house? Hope you get it sorted.
My dp is quite bad at not doing things when he says he will.
I find the trick to motivate him is to start doing it myself. For example, if I wanted him to draw up plans, I would tell him I had booked an appointment with an architect and it was going to cost xx amount. I would make it clear that I was sorting it out. I don't know about your dh, but the thought of spending money where he didn't need to would be enough to motivate my dp.