“The Internet of Things (IoT) is an incredibly hot topic, and interest is so great it may have obscured the central truth about IoT: It isn't about the things themselves; it's about being smart. It's the application of intelligence to sensor data that makes IoT useful and real -- especially in the context of a building,” says Tom Nolle, President of the CIMI Corporation, a strategic technology consultancy founded in 1982 that serves the networking and IT industries.

Sensors and data without “smartness,” or advanced analytics, as Nolle suggests, would be relatively useless. However, so is intelligence without data. What Nolle is putting forward is that the top layer, the “smartness,” should be the main focus of system architecture design and development. In contrast, he implies, to the current fragmented situation we find ourselves in through our bottom-up approach to smart buildings and cities.

“The most important truth about today’s smart buildings is that they aren’t designed from the top-down but assembled from the bottom-up. That’s because security, facility controls and other IoT systems found in smart buildings are generally independently designed and deployed separately,” Nolle said in an article for the Internet of Things Agenda. “To truly garner the benefits an IoT smart building has to offer, it’s critical to take a top-down approach and have all IoT systems working together.”

The criticism of top-down approaches has, in general, been that they do not represent the needs and desires of the bottom layer, the users. Designed from the top, systems become authoritarian, deciding what’s best for the user, rather than allowing solutions to emerge organically in response to problems encountered by users and occupants, the people who actually use the system. This translates to the system architecture too.

Timing and approach to technology adoption, even the selection of vendors, is all part of that organic, bottom-up, style of development that responds to actual needs and better engages users to support implementation. The “top” is also fundamental to integrating systems, allowing them to work seamlessly for the benefit of the end user and the overall objectives of the building. The bottom is what makes a building a building, the top is what makes a building smart.

“The real smarts in a smart building are created by the element at the top: a device that manages the flow of data, which I'll refer to as the facility controller. This is likely a collection of applications running on traditional servers or in the cloud, and it connects at the bottom to the APIs exposed by the IoT system hubs of the building's IoT deployments,” Nolle explains.

“In most IoT applications, the facility controller doesn't provide system-specific details but rather integrates across systems to build a higher level of control intelligence. It's this facility controller that creates smart buildings, and a hierarchy of these facility controllers turns smart buildings into smart complexes -- and eventually into smart cities,” he continues.

The smart city can be viewed simply as a collection of smart buildings surrounded by smart infrastructure. Smart cities, according to the views of many leading experts, should also follow a bottom-up approach, where buildings develop independently and then integration is developed between each building, their neighborhood, and the wider city. Even smart infrastructural development can be guided by the citizens themselves, rather than imposed on them by the “top” - albeit within a centrally controlled infrastructure network.

The fear is that a purely top-down approach to smart buildings and smart cities will lead to the same system architecture model being applied everywhere or, at least, a limited number of templates applied to every building and city. None really fitting the unique needs of their environment, nor engaging citizen/occupant users, nor creating the competitive environment that drives development.

Bottom-up is organic and personal but also dynamic and chaotic. While a purely bottom-up approach will be fraught with integration and implementation challenges, and in a constant state of one kind of disruption or another; it will, over time, create a space that represents and serves the people that use it. Those users feel more engaged in the system, having been part of creating it, which in turn leads to easier technology implementation and better outcomes.

“The goal of the industry's work on smart buildings, plants and cities is not to force an identical implementation on all these things, but to define a common architecture that will permit the use of common software components for as many of the functional layers we've discussed as possible,” Nolle says in his post. “Facility-wide correlation of events and the coordinated control of multiple systems are the leading edge of IoT. That correlation starts with the smart building and so should IoT planning.”

While making a strong case for top-down IoT development, Nolle does not address the insufficiencies of the approach, nor does he highlight the benefits of more bottom-up methods. His focus is on creating the “smartest” building system possible and, in doing so, provide a seamless experience for the occupant. However, no smart building can succeed without input from the bottom, be that from users at the design and operational stages or in terms of data from strategically placed sensors.

Smart buildings and smart cities must draw data, inspiration, and direction from the bottom-up and then hope to integrate those fucntions smartly from the top. Industry figures can try to describe there approach as top-down or bottom-up to differentiate from one another, but only a balanced approach that engages the bottom while governing from the top can create a truly successful smart building.