Doing Your Own House Design Plans
Some people draw up their own plans. Unless you are specifically trained in residential design, you will probably not be totally successful in doing this. That is, your drawings will probably have to be re-drawn by a draftsperson so as to include all of the details needed to actually construct your new home.
You may, however, find it more difficult than you had anticipated. There are a lot of dimensions and relationships that are critical. If you don't know what they are, you may end up with a design that really doesn't work and can be costly to correct after construction begins.
A better alternative would be to explore some of the house plan software that is readily available. These programs will give you a professional looking set of plans and will often calculate the materials you will need. You may find them limited if you have local conditions which dictate construction techniques not included in the program and some don't allow for normal inherent waste factors.