Glass buildings under a cloudy sky

How Old Wires Are Bringing New Efficiencies to Building Retrofits

by John Lannan & Margaret Naughton

In the first blog in this series, we spoke about the importance of bringing digitalization to buildings. Today we are going to talk about existing buildings and the benefits of retrofits. 85-95% of all buildings within the EU today will still be standing in 20501, this stat alone highlights the importance of retrofitting buildings in the coming years.

 Stats of existing buildings standing by 2050

A retrofit of an existing building brings both opportunities and challenges. The challenge is to work within the existing constraints of the physical space, and the opportunity is to reuse existing assets – reducing installation time and cost.

A key consideration when upgrading a building management system (BMS) is what connectivity solution to use. With increasing levels of data being generated and decision making happening in every corner of the building, internet protocol-based communications, such as Ethernet, are gaining more traction in the building management space. The 10BASE-T1L IEEE standard for Ethernet (802.3cg) offers the ability to extend Ethernet range up to 1,000 meters, bringing Ethernet to places in the building management system where only serial or analog communications could reach previously.

Ethernet brings several advantages over legacy serial communications: higher bandwidth, addressability, higher node counts, and a full suite of security solutions developed for IT applications. Because it only requires a single pair of wires, 10BASE-T1L allows for the re-use of the existing RS-485 cabling within a building. Not only is the old wire not ripped out and thrown away, but it may also be reused. Single pair cables typically use screw terminals on the controllers and connected equipment, which means when upgrading to Ethernet there is no need to crimp cables for RJ45 connectors, which can be time consuming and costly.

 security solutions developed for IT applications

Another characteristic of building retrofits is the need to be flexible and adapt to changes as the installation of the building management system unfolds. One way Analog Devices is addressing this challenge is to make universal input/output circuits easier to implement on building equipment. This allows a terminal on a controller or piece of equipment to be configured on the fly as an analog input, analog output, or digital input (digital outputs are also possible with additional external circuitry). This simplifies the design and manufacturing of the controller and I/O modules, reducing the number of SKUs that need to be manufactured and stocked. ADI’s AD74412R Software Configurable IO (SWIO) is the ideal starting point for anyone considering adding the first step of flexibility in IO to an existing building, with functionality for analog output, analog input, digital input, and resistance temperature detector (RTD) measurements integrated into a single chip. This creates a path to 10BASE-T1L adoption and the potential for newer technology like Single-pair Power over Ethernet (SPoE) to be incorporated as it becomes more commonplace in the coming years.

Retrofits of existing buildings that improve efficiency will play a valuable role in the global fight against climate change. Analog Devices offers innovative new products to specifically address the challenges of building retrofits, while also being able to reuse some of the building’s assets – reducing waste, minimizing installation time, and lowering installation cost. To learn more visit

Find the next blog in this series here and if you missed the previous blog you can find it here.