When you're not home, nagging little doubts can start to crowd your mind. Did I turn the coffee maker off?  Did I set the security alarm? Are the kids doing their homework or watching television?

With a smart home, you could quiet all of these worries with a quick trip online. When you're home, the house takes care of you by playing your favorite song whenever you walk in or instantaneously dimming the lights for a movie. Is it magic? No, it's home automation. Smart homes connect all the devices and appliances in your home so they can communicate with each other and with you.

Anything in your home that uses electricity can be put on the home network and at your command. Whether you give that command by voice, remote control or computer, the home reacts. Most applications relate to lighting, home security, home theater and entertainment and thermostat regulation.

Smart Home Software and Technology

Smart home technology has been around a lot longer than you may think.  It was first developed in 1975, when a company in Scotland created X10.  X10 allows compatible products to talk to each other over the already existing electrical wires of a home. All the appliances and devices are receivers, and the means of controlling the system, such as remote controls or keypads, are transmitters.

Today, X10 is not the only technology available.  Instead of going through the power lines, some systems use radio waves to communicate, which is also how WiFi and cell phone signals operate. However, home automation networks don't need all the juice of a WiFi network because automation commands are short messages. The two most prominent radio networks in home automation are ZigBee and Z-Wave.

When it comes to smart homes you basically have two options.  If you happen to be among the wealthiest people on earth, you can consider the elaborate designs incorporated into Bill Gates home, as illustrated below:

At the other extreme are things that can be done today - with current materials and technologies.  Currently on display (through January 2009) at the Chicago Museum of Science and Industry is an example of a modular smart home of approxiatley 2,500 square feet of living space.  The three-story prefabricated home showcases how sustainable materials, "smart" automation of lighting and HVAC systems, and eco-friendly practices and products can fit into any home owner’s lifestyle. Some of its features include:

Central Everything

From a panel on a wall, you can control and monitor all your home’s systems and review energy and water use from a central point. System can achieve optimum comfort with minimal power usage by coordinating lighting, window coverings, heat, and air conditioning. The home also includes built-in Wi-Fi, a housewide audio system, and electronic security.

Sustainable Living

Large windows, sliding doors, and multi-story skylights can take advantage of natural light and make the space look larger, a sense heightened by neutral palette colors throughout. Home can also features a green interior, with low-VOC paints, bamboo flooring, and furnishings made from recycled or renewable materials. For example, recycled t-shirts can be used for sofa upholstery or furniture can be made from recycled wood and fallen trees.

Roof Top Power, Insulation

A green-roof garden of drought-tolerant plants can provide year-round insulation, while solar panels can harness the power of the sun to provide most of the home’s electricity. Innovative photovoltic film works in shade and even generates electricity through much of Chicago’s cold, cloudy winter. At ground level are native plants and water permeable pavements; rain barrels are used to hydrate the garden, conserving drinking-quality water.