While serving as essential features for just about any habitable built environment, windows can also be a major liability for both the energy efficiency and security of a property.

Building occupants are often inclined to leave windows open during spells of sweltering weather or in order to ventilate stuffy indoor environments.

Given the large number of windows that many buildings possess, however, as well as the often distracted and forgetful nature of the human mind, it’s not unusual for windows to be left open under circumstances when they should be firmly shut.

In highly changeable climates, for examples. windows that were opened during warmer parts of the day for cooling or ventilation purposes can become an energy suck on heating equipment should they still be left open when weather outside abruptly turns cold.

Open windows are also an obvious security hazard, providing a convenient route of potential access to thieves and intruders.

The energy efficiency and security problems that open windows can create are especially pronounced in modern Australian buildings, given the legal requirement that any “habitable” rooms possess a significant amount of window space.

The Building Code of Australia (BCA) states that a room must possess windows whose dimensions are equal to at least 10 per cent of floor area in order to be deemed “habitable.”

Thankfully for property owners and occupants in Australia, a convenient technology now exists to help prevent any of the potential problems associated with open windows.

Sensors that communicate with smart building systems can be installed in windows, irrespective of their shape and dimensions, in order to issue an alert to occupants when the windows have been left open for too long, or are still open when occupants are preparing to depart.

More advanced sensors are capable acting as highly discriminating alarm systems, capable of distinguishing between innocuous taps or bumps and more forceful efforts to pry windows open.

The sensors can be connected to the smart systems via cables, or they can employ independent, battery-operated radios for increased ease of installation.

At the very cutting edge of development are tiny, solar-powered sensors developed by German researchers at the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg.

solar-powered sensor chip

solar-powered sensor chip

At ten millimetres in width, the solar-powered sensor chip is no greater than a fingernail in size, and can be attached directly to the aluminium profile that lines the window panes.

The chief advantage of the device is its ability to power itself independently using the sunlight is receives by virtue of its position adjacent to the window, even during cloudy and inclement weather. This saves building owners and managers from the hassle of installing cable systems for the sensors, or changing their batteries on a regular basis.