This is one question every home builder have asked at one time or another. And it isn't the easiest question to answer. In fact, if you look at any airplane trading papers or home building magazine, you will see something like this.
"For Sale: 90% complete Garage Queen 2000. All parts and instructions complete."
This is one of a good indication that the builder have answered the first question incorrectly. To answer the question, let me discuss some of the wrong reasons to homebuild.
So why bother?
So, the #1 requirement for successful homebuilder is that they have to enjoy the process of building itself. Even with modern fast-build kits, it is a phenomenal undertaking and unless you love working with your hands, chances are you will be taking out a classified ads after the kits sits in your garage for several years. The process of building is also the objective.
Then, you'd have to be resourceful. There are times you will not have the right space, tool or equipments. Creative problem solving is a large part of building a plane. You don't want to be too resourceful to the point you will be making dangerous shortcuts or substitution. But if you are too rigid in your thinking, you may end up waiting long time before that 'perfect piece of nut' shows up on your doorstep.
If you have a spouse, partner, relationship, family, jobs, or anything in your life that require your attention, it might be a good idea to get their 'buy-off' first. The project will take a lot of your time and energy. If you are going to be building in your residence, then it will take up space that are probably used for something else right now. There will be noises, fumes, dust, and refuse that are the by-product of your project. Your partner may be irritated by clutter of all the parts stored in the house. They may, over time, get resentful of all the money that will inevitably get diverted to items they cannot identify. You may need to set a limit to get a buy-off. If this is the case, then stay within the limits. Abusing or constantly testing the limit would only lead to growing resentment over time.
Homebuilding isn't for everyone. That's why you see so many projects being sold off all too often before completion.