With 3D house design, you get a great understanding of how your house will look, both internally and externally. It’s an opportunity to play around with different internal configurations before you commit to the final floorplans. You can populate the house with furniture and furnishings from giant image libraries and experiment with different colour schemes.
With many 3D applications, you can orient the house to the geographical location. This allows you to check how the internal light changes as the (artificial) sun rises and sets about your house. Nowadays, you’re no longer looking at wireframe images. Modern techniques allow you to apply textures and lighting with the result that the display is close to high-quality video.
If you intend to appoint a designer, it’s worth asking if they produce a 3D model that you can experiment with. You might also ask whether they offer a texturing service also; it will bring the design to life.
If you want to prepare your own 3D model of your house, it’s not that difficult, especially using Sketchup 3D modelling software.
Marc Almond, the founder director of efkor, has written a book “The Nested Matrix: Rapid Modelling of 3D Residential Structures, using Sketchup” which would help you to model your own house; it requires no previous knowledge of building design or CAD. You can find more information here.