The second reason is because you want to make sure that you know what exactly is out there and not just pick something out because it is the last minute. Picking things out before hand helps you to be able to do some research and see what products are better then other products,

The third reason is so that you can coordinate things. You want to make sure that you are not just throwing things together because you don't know what options are out there. You want to make sure that you take the time to look around and get ideas. For example go to the parade of homes or different model homes and see what colors of paint they have and what different floorings and counter tips they have with what color of cabinets. This will help you to start to get ideas of what looks good together and what should be left alone. Once you at least have an idea you can go from there and start to build your own idea on top.

The fourth reason is so that you can design certain things for the look that you are going for. For example if you have picked out a certain sink to go in your bathroom to complete a certain look you want to make sure that from the start that your look is achieved from how the room is designed to what cabinets go in it to the tile. You want to make sure that everything is complete so that you achieve the look that you are going for instead of only getting the partial look.

The fifth reason is so that you can get an idea of what type of house you want to complete the look. For example if you want a rustic home with rough cut timbers and beat up cabinets and furniture you are not going to want to build a Victorian style home because it is not going to look good together. You want to build a rustic home with the right color of brick, rock, or stucco that is going to help make your home complete.

The sixth reason is so that you know what if you want a fireplace or not and if you do you need to make sure to look for a plan that includes a fireplace. Or if you want a walking in shower and you already have the fixtures you want you can find a plan that includes the shower you want or you can have the plans changed to include it.

These are just some of the reasons why you need to decide what you want, before you build. There are so many other reasons. Make sure that you take these into consideration so that you are not unhappy when you start building and realize you should have decided what you wanted earlier so that you don't have so much to worry about now.