Designing buildings for the Internet of Things

The networking of things within a building must be anticipated by building engineers.

By Tim Kuhlman, PE, RCDD; TEECOM, Portland, Ore. June 26, 2017

Learning Objective

  • Understand the basics of Internet of Things (IoT) and how its evolution will impact building systems. 
  • Anticipate IoT’s influence on building systems, infrastructure, and the evolution of design.

In the past few years, the term “Internet of Things” (IoT) has become the favored buzzword to describe the next stage of evolution of the information age. This is an abstract term, which makes the concept more difficult to understand. How does this abstract term affect building design? It would make more sense to use the term as a verb, such as “the internetting of things,” or simpler yet, “the networking of things.”

What we are really talking about with IoT is taking items or devices (things) and connecting them to a network where the items have access to information. The devices will use the information in differenent ways. The simple devices will interpret and display information. More sophisticated devices will receive information from their environment and communicate it back through the network. The most sophisiticated devices have integrated logic or intelligence to perform control functions and to interact with other devices. How can we anticipate the impact and trends of IoT so we can extrapolate its impact on infrastructure? Let’s start with an analysis of probably the first IoT device, the cellular phone, to see how it evolved.

The cell phone didn’t start as an IoT device, but because of its access to the cell phone wireless network, it was in the unique position to become an IoT device. From the early 1980s to the early ‘90s, cell phones only handled telephone calls. During this time, cell phones had access to the telephone network but not the internet.

In the early 90’s, we saw the birth of the web and smartphones. When phones could be used to access data from external data sources, they became an IoT device. As an infant IoT device, cell phones could be used for email and text messages. They eventually grew into web browsers. Currently, smartphones are only limited by the applications loaded on them. Communications and access to data were key to cell phones becoming smartphones. Today, cell phones have multiple wireless modes (cellular, Wi-Fi, Bluetooth, and others) that allow them to exchange data from the “cloud” and control other devices near and far.

The cell phone is just one example. Consider the following: We have cars that can communicate to a dealership when they need service or if they are in an accident, vending machines that tell the distributor when they are running low on product and allow payment via credit card or mobile phone wallet, and televisions and DVRs that automatically check for software updates from the manufacturer.

As architects and engineers, we need to anticipate IoT trends as we design facilities. IoT devices will continue to become more popular for personal use, business applications, and facility operations. There is an expectation that the facilities we design today will be able to support IoT devices without needing to be redesigned.

Disparate lifespans

In considering a facility design that supports IoT, the challenge for the designer is anticipating the technology trends for key building components with different lifespans. Cell phones as IoT devices do not actually wear out in 18 months, but they are driven to obsolescence by the introduction of new technology and competitive market forces. A cell phone battery has an estimated life span of 2 years, but when faced with the choice of replacing the battery for 10% of the cost of a new phone, often the choice is to replace the phone to take advantage of the technology improvements. Of all IoT devices, cell phones probably have the shortest lifespan.

They also represent a new category of devices in the workplace, often referred to as “bring your own device” or BYOD. This could apply to personal laptops, tablets, or other electronic devices that are owned by a person but used in a facility to conduct business. Whereas a company may have a corporate policy to replace an employee laptop computer every 4 years, a person who brings their own laptop may decide to replace their laptop every 2 years. This implies two things: The IT network must be adaptable to newer technologies, and the IT department may not be in control of their technology rollout.

Internet vs. intranet, wired vs. wireless

As the term implies, IoT devices are connected to the internet. This is not always true. This is another reason why IoT devices should be considered the “networking of things.” Besides accessing data from across the internet, an IoT device may access data from a local network (intranet) or exchange data locally with a peer device. It depends on where the device is and where the data is located.

IoT devices can be wired or wireless. This all depends on the device and how the device is used. The trend is for an increase in devices to be wireless. Wireless allows for more flexibility for mobile devices; for stationary devices, it eliminates the cabling. The biggest drawback of wireless devices is the source of power. IoT devices are not inherently passive. They require power from a battery or an external source. There are new devices, however, that have integrated photovoltaic cells to allow for recharging from ambient light sources.

Wired IoT devices in need of a power source can use the same data cable that is used to transmit and receive data. No external power supply is necessary. This uses a Power over Ethernet protocol or some other Class 2 or Class 3 power source in the network room. Current technology allows for a device with a single cable to communicate with video, data, control signal, and power just shy of 100 W.

Related to IoT, another big user of wired devices is the wireless infrastructure. To make wireless devices work, they need to communicate with a cellular system or a Wi-Fi network. Within a facility, this will likely be through the building Wi-Fi network. Each wireless access point (essentially a radio) requires power and data. The more devices communicating in one area, the greater the number of wireless access points needed to maintain a quality of service. The trend in wireless is for a higher density of wireless access points with a higher bandwidth (more radio channels) and needing more power.

How buildings need to adapt to support IoT devices

One way to consider the impacts of IoT devices to the facility design is to work backward from the IoT devices. IoT devices in a facility will be wired or wireless, and there are still a lot of wires needed for wireless infrastructure. All these wires go back to the network communication room. The cabling takes space in the network communication rooms and in the pathways getting back to the rooms. Both the pathways and the rooms need to be designed with growth in mind. A good rule is to allow for 100% growth for the horizontal cabling spaces (cables going from a device back to the network communication room) and 50% growth for the backbone cabling spaces that interconnect the network communication rooms. This allows room for growth in both the network communication rooms and cable trays.

Both the IoT devices that are wired and the wireless access points need power. This power also will come from the local network communication rooms serving a building zone. If more power is being transferred through the network communications rooms, some of that power will turn into heat in the rooms, which implies more heat rejection is required.

From an architectural viewpoint, assume the network communication rooms will continue to increase in size. The technology engineer should design a room for the equipment being installed on day 1 as well as for equipment to be added over the lifespan of the building. Based on product lifecycles, it may be necessary to refresh the network several times over the life of the building. The network communication rooms should house all network equipment, whether it is for private use or public-access networks.

For example, a company may decide not to allow public IoT devices to access their private network or even their guest wireless private network. Mobile IoT devices can communicate with multiple types of wireless protocol. They may be able to communicate over a cellular network if a public-access Wi-Fi network is not available. Extending the public cellular networks into a building through a distributed antenna system is common. This equipment takes space, requires power, and should be integrated into the network communication rooms.

The electrical loads for the network equipment will continue to increase. The power system should be designed to allow for scaling up and the addition of power circuits. The mechanical or HVAC system for the network communication room also should be scalable. This does not mean the HVAC system should be completely built today for the future load. However, depending on the system, some techniques can be built now to lessen the impact of scaling up in the future, such as oversizing a chilled water line in anticipation of additional taps or installing additional refrigerant lines in anticipation of a future direct-expansion unit to be installed.

Scalability can be applied to the architectural design of the network communication rooms. When working with the technology engineer to locate the network communication rooms, avoid locations where the rooms cannot be expanded, such as next to exterior walls, vertical shafts, and stairwells. Strategically locating a small conference room next to a network communication room would allow for the network technology room to grow into the conference space in the future while minimizing impact to the floor space.

Technology can’t wait for tenant improvement

The traditional building design mentality of considering the building technology to be part of the tenant-improvement phase of the project will not prepare facilities for future technologies. Architects and engineers should be engaging their technology partners at the beginning of the project. The technology disciplines (telecom, security, building automation, and lighting) have been going through a convergence over the past several years, with telecom wired and wireless networks becoming the common utility for all the technology disciplines.

Where these systems were once considered separate and required their own space for equipment and pathways, they are starting to share more of these spaces. This has an impact on the architectural layout of the building and the concentration of loads on the electrical and mechanical systems.

The next step is the evolution of the technology systems into the architectural building interiors. Imagine a building area where the ceiling, raised access floor, or wall systems are integrated with the technology. Interior finishes can incorporate wireless access points, LED lighting, building automation sensors, and security devices in a modular system. Instead of an architect having their vision for an interior space be pockmarked with wireless access points and other technology devices, they can choose a design where these components are integrated.

Anticipating the next step of IoT evolution

Predicting the future is difficult, but there are a couple of emerging technologies that show promise for IoT. The first is in the realm of artificial intelligence and automated response. Siri is Apple’s intelligent assistant, which was released in 2011 for several Apple platforms. It is a program that can adapt to a person’s search routines and use of language. With Siri, you can ask a question and the program can serve up data compiled from the internet. Now imagine going to a concert and trying to find your seat. By logging into the venue’s guest wireless network and accessing the venue map, Siri can direct you. Or, imagine visiting a client’s office complex and having Siri direct you to the correct conference room.

There are other artificial intelligence systems, like Alexa, which interacts with Amazon’s Echo. Devices such as these currently work independently; the next step is for them to be interconnected and more thoroughly integrated into our surroundings or building systems. In addition to Alexa learning my voice and my desired light level for a room, a network of Alexas would be able to respond wherever it recognizes my presence.

Another promising step for IoT is the use of mesh networks to interconnect IoT devices. In a mesh network, every node interconnects with a nearby node to pass data. Mesh networks can be set up to be self-recognizing and self-healing. This allows new devices to be introduced as they encounter the rest of the network, or for the network to transfer data along an alternative path if a node is removed from the mesh. This technology has been around for a while for wired networks.

The next step is to see wireless devices create mesh networks with other wireless IoT devices in the vicinity. It may not be possible for the network Wi-Fi to reach every place in a building, but through the wireless interconnection of nearby nodes, IoT devices can act as digital repeaters.


Tim Kuhlman is an associate principal at TEECOM, where his focus is designing telecommunication systems for commercial and industrial facilities. He combines his 6 years of construction experience with 23 years of engineering to expertly solve complex problems for his clients. He is a member emeritus of the Consulting-Specifying Engineer editorial advisory board.