Contrary to the impulse toward centralization, there is an opposite tendency in the industry toward encouraging batteryless microsensors blanketed across buildings and connected wirelessly using the emerging Zigbee wireless standard. Osman Ahmed, a senior principal engineer with Siemens Building Technologies, believes the new controls will be a single control - Micro-Electro Mechanical Systems (MEMS) - that will contain up to five sensor channels and be so small as to be almost invisible. Embedded MEMS in drywall could sense for temperature, humidity, and VOC levels and wirelessly transmit the data to a nearby control device. Although it's not yet commercially available for the company's APOGEE wireless system, Siemens has developed a sensor that can measure mean radiant temperature and is so small it could be embedded in a pane of glass. "You could change the properties of your glass with an applied voltage based on whether you wanted more or less solar gain," Ahmed says.

Ahmed describes MEMS as being like a peanut-butter-and-jelly sandwich. Silicon wafers act as bread to sandwich layers of materials that react only to certain other materials, such as CO2, for example. As a molecule of CO2 passes through the jelly layer in an absorption process, it changes the voltage of the MEMS just enough to register and be transmitted to the larger control device, where it's amplified into a more readable set of data. The CO2 molecule is then released again on the other side of the jelly, which is important, since it ensures the jelly will not become bloated with CO2 molecules and desensitized, Ahmed says. Because they are so small, such devices can generate their own electricity through slight vibrations in duct work or the building in general. Ahmed says this approach to sensing could improve accuracy overall, since the devices will eventually be so cheap that buildings will contain hundreds, if not thousands, of control points that can then be measured and compared to one another. Anomalies would be singled out quickly, and those sensors could be deleted from the network. Ahmed estimates such technologies will reach the market in three to five years, assuming a manufacturing base for such specialized components develops.

If the industry can seem fragmented in its development of these systems, it may have to do with the frontier mentality that has swept in as prices of Web-based technologies have fallen and controls infrastructure has become more consolidated. Before experimental systems like those of Ratti or The Living become everyday projects, industry sources agree they need to offer more assurance that the systems can be maintained, secured, and open enough to be useful. Conversely, if architects ignore such developments, they risk marginalizing architecture's role in the digital world. "We're cultivating new generations of people who are going to be very savvy about hacking things," says Clemson's Green. "Technology is such a part of our lives and we need the mind of the architect to reflect and ponder what we want this to be."