Building?

I'm starting to get used to building in TS3, but I'm having difficulties building those awesome ultra-modern houses. They look really simple and just a couple of boxes on top of each other, but then there are houses I would like to re-create like some of the easier looking ones on this website: [You must be registered and logged in to see this link.]
Does anyone know of a tutorial or any advice of how I can build really great modern houses. I would just download, but they're all two or three bedroom and I like to have four or five bedrooms. I would also like to know because I am planning to do a legacy soon and I would like to have one of these houses when my legacy family can afford it

Thank you to anyone who replies