Anyone who is considering working at home has to recognition that in the office the whole workplace conspires to help you do your work. When you are home, you will find that it is just the opposite. At least, it will seem as if everyone wants a bit of your time and take you away from your work.
Given the difficulty, it might be wise to sit down with the family and make decisions about the time that will be needed to carry out the work and the time remaining for family needs. Declaring unilaterally that you will work from 9:00 a.m. to 5:00 p.m. will cause a lot of conflict.
Distraction and procrastination, if problems, will have to be addressed. So will consideration of work style. For instance, you may work best in short bursts of activity, whereas trying for long sustained work goes against your nature. Under these circumstances, you might want to organization your work day to have numerous subprojects so you can shift from one task of 30 minutes to another of an hour and so on through the day.
An alternative approach is to organize the workload by day. Immerse yourself in work one day, working straight through lunch to complete a major project and then, on another day, visit clients, make phone calls, and send off emails, organize files, and complete all those other small tasks associated with work.