If you have decided to design your own house you'll need to start looking at many different styles and decide what will suit you best. If you want to incorporate ecological sustainability within your design, then you might want to also go to the Eco Sustainable Design section to get some more ideas. A passive solar design will have a large impact on the kind of layout your house will need to adhere to. Look around where ever you are and assess the spatial qualities of the rooms you currently inhabit.
In each room you enter from now on ask yourself these questions.
How do I feel in the room?
Is there good natural light? Where is it coming from?
Is the room ergonomically successful? Is it easy to function in?
What materials are on the walls, floor, ceiling and surfaces?
What shape and size is the room?
Keep a list of things that stand out to you both good and bad in your work book.
What about the house as a whole?
Where will you enter the house? Do you need an entrance hall?
How will you move around the house
Which rooms need to be close to each other
Does your family like to have dinner parties? How big should the dining room be? How close to the kitchen?
Do you have lots of young kids visiting?
Where is the washing line going to be? How will you get to it?
Ventilation in each room and through the house
The relationship between formal and informal spaces
It is a good exercise to get some cardboard and write down all the different rooms you expect to have in big writing. Then cut out each room name and place them on the table in front of you. The idea is to get to know which rooms you'd like next to each other. Move the pieces around until you have the best possible solution and then stick them in the exact order in your work book. If you hire an architect this is the kind of thing you can give to them.
Planning a house is a difficult task and there are many different ways to go about it. It is likely that you have lived in both open plan and traditional types of houses, if not try to visit some so that you get an idea of what's going to work for you.