I would not mix LED and CFL they have different looks and LED s are much cheaper to run. You can find a fixture you like and switch out most with LEDs, we have been slowly changing all of our halogen lighting to LEDs now that the LEDs come in higher wattages. We have 70 halogen lights in our house so I am doing 12 at a time, love the change. I like the fact that you can have a lot more lights off the same circuit too.

A thick concrete wall can keep your house cool. Steel will make your house hot unless you insulated the walls well. Insulated walls don't work very well in a flood zone. When they get wet, you need to tear them apart. You will need concrete for the foundation most likely unless you are driving steel pylons. There is probably a combination of the two that will suit your needs best. It would be helpful to know what you want to achieve by using steel. There are advantages to both. Steel floors can be cantilevered further. It is easier to make bigger window openings. Floor and roof spans can be lighter and quicker to build with steel, but the roof will get hotter and therefore need good insulation and need to be well ventilated. These are just general assumptions of certain building practices so that you know what to ask people where you live. The practices and resources vary from place to place and building something for a specific purpose can change the benefits of one material or the other. My best guess is that you will probably want to use both.

The energy efficient bulbs shown in the above photo suck the light is awful and they butn out quite often, if you want real energy savings go with LEDs they come in warm or cool light and you probably never have to chang a bulb as long as you live. They come in all kinds of wattages and can be retrofitted in almost any fixture.

Congratulations to all of you. Its a wonderful platform to be on and you all are doing a great Job. My favourite Design Style is 'Minimal'. I just have this strong connection with simple, subtle and elegant things. Cheers:)