One problem to consider if you are working on your startup from home is the danger of constant interruptions. It can be hard on your family, especially your wife, to "not be allowed" to interrupt you. You have to remember that your family interrupts you because they care about you and they want you involved in their lives, but at the same time you have to find a way to tactfully get them to stay away from your office during your workday.

Sitting almost perfectly still in front of a computer and concentrating for hours and hours at a stretch is not a natural act. Humans are wired to get involved with the social activities going on around them. Depending on the difficulty of what you are working on, a few family interruptions per day or a too-high noise level from elsewhere in the house can destroy the quality of your work for the entire day.

Interruptions are also a big problem in a traditional office environment, but there you have much less invested in your efficiency. If management isn't willing to pay for private offices where the staff can concentrate properly -- then they get what they pay for and its not really the programmer's job to question it. At least everybody in a shared office area is in the same boat and everybody suffers from the same distractions.

In a startup, however, interruptions can ruin you and must be dealt with.