Sustainable Future

Top 10 Retrofit Methods for Sustainable Buildings

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The environmental impact of buildings has become increasingly apparent. Many organizations recognize the value of green buildings and sustainability as part of their responsibility to more than just the bottom line. Green or sustainable practices within commercial buildings produce healthier and more resource-efficient models of operation and maintenance. 

Certainly, a building doesn’t have to be new to be efficient. The number of existing, in-service buildings dwarfs the number of new construction projects. Retrofits for existing buildings can therefore produce outsized environmental impact as compared to a focus solely on green design and construction practices.

Green building retrofits deliver proven results with minimal cost. While they may not deliver catchy headlines common amongst trophy construction projects, their pervasive impact across the building landscape has raised the profile of building sustainability in the consciousness of the general public. Green practices should represent more than an event; they should produce a discernible shift in day-to-day corporate responsibility.

Today’s leading building owners have actively engaged green building retrofits as the key to future models of sustainability. More than narrow vertical products, horizontal platform approaches have driven investment in bundles of technology that interoperate to deliver deeper efficiencies with a comprehensive approach.

Here are the top 10 retrofit methods that can guide your way to sustainable building practices.

1. Real-Time Visibility to Energy Consumption

Energy efficiency represents a well-known principle that forms the foundation of any green building proposition. Too many existing buildings provide little to no visibility into the real-time energy consumption of different areas of a building. In today’s climate where real-time products and services represent the norm, managing energy consumption retroactively based on a monthly utility bill seems preposterous. The entire CRE industry believes in energy efficiency; they simply lack the tools to execute.

Internet of Things (IoT) retrofits routinely deliver real-time insights into energy consumption both at the whole-building level and at a tenant or equipment level. IoT retrofits can roll out incrementally at a fraction of the costs of upgrading existing infrastructures.

Anytime Anywhere AccessWithout question, energy efficiency programs should go beyond the main utility meter. Submetering delivers the needed granular insight. Even if your building has a Building Automation System (BAS), you still aren’t in the clear. Most existing buildings have a BAS that cannot deliver real-time visibility to utility submetering data. Even more problematic is gaining anytime, anywhere access to that data via your mobile device. Cloud-based IoT solutions can deliver real-time visibility to everyone in your organization, regardless of their location on-premises or off-site.

2. Water Efficiency 

Water efficiency represents another foundational principle to green buildings. Geographic areas facing acute water shortages make this a non-negotiable issue. Managing end-use water consumption can take a variety of forms.

Cooling towers represent one of the largest consumers of water in a commercial/industrial building. Any green initiative that takes water efficiency into account should monitor and optimize the operation of the cooling tower. An example usage profile can be calculated as follows based on the Chiller tonnage:

Daily Cooling Tower Water Usage Rate

Example of Daily Cooling Tower Water Use at Full Load (Gallons Per Day)

As illustrated, the daily water usage can range into hundreds of thousands of gallons. Without real-time visibility into the operation of the cooling tower (e.g., blowdown, system leaks, and drift), how else can a building claim that green building practices have been incorporated? Low-cost IoT retrofits can provide needed insights through asset digitization (or digital twins) of the cooling tower and chiller to achieve true water efficiency.

3. Continuous HVAC Commissioning

Scheduled performance checks on HVAC equipment do not necessarily equate to re-commissioning of the HVAC system. Performance of the HVAC system will drift over time. The resulting inefficiencies can result from insufficient maintenance or changes in the use of a building. Building areas that were once comfortable can become insufficiently or overly cooled/heated leading to occupant complaints. Without questions, energy efficiency would suffer in such a scenario.

Continuous commissioning formalizes the process of ensuring that your HVAC system runs at peak performance levels. This ongoing process is designed to resolve operational problems, improve tenant comfort, and optimize energy use for existing buildings. Continuous commissioning can also significantly extend the useful life of HVAC equipment. Continuous commissioning will rescue your HVAC efficiency.

4. Green Roof

Green roof installation“Green roofs” represent specialized roofing systems (see Example to the right) that support vegetation growth (e.g., grass, plants, flowers, bushes and other greenery) on rooftops. Numerous benefits can result from implementing green roof technology in an urban area. For example, a green roof can reduce site level storm water runoff, lower a building’s cooling/heating energy demand, and reduce the urban heat island effect from the building. Extensive green roof systems have gained in popularity because they are lightweight, low cost and low maintenance. Green roofs easily check the “Green” box of building sustainability.

5. Indoor Air Quality

IAQ has become entrenched at or near the top of modern tenants' list of concerns. Occupants’ health and productivity concerns invariably link buildings and IAQ closely. According to the US Environmental Protection Agency, people spend approximately 90% of their time indoors, breathing indoor air more polluted than outdoor air. Any “Green” practice that removes pollution from the indoor air will be well received by all stakeholders in a building.

Recent scientific evidence proves the adverse effect IAQ has on people’s health. Poor ventilation, improper control of heating and cooling, and recent remodeling can affect the building's fresh air intake. Contaminants like dust, mold, cleaning supplies, pesticides, or other airborne chemicals can cause hazardous IAQ. Green building retrofits can deliver real-time IAQ monitoring in your building to comply with new building standards such as WELL.

6. Operations and Maintenance Optimization

While a building’s design and construction may have focused on sustainability, it can only remain so if it is operated responsibly and maintained properly. Operations and maintenance (O&M) personnel represent the key to actually sustaining a building. O&M personnel perform best when they operative proactively rather than reactively. At every level of facility management, real-time visibility of the operational status of different parts of the building (i.e., Mechanical, Electrical, Environmental, Plumbing) can lead to preventative maintenance rather than emergency repairs. The lack of visibility to operational data is the largest deterrent to green building practices.

7. Load Curtailment Programs

Buildings do not exist in isolation. Energy efficiency reduces utility costs to the building owner, but does not consider the state of the power grid itself. Green buildings can participate in demand response or load curtailment programs, which reduce electricity usage for brief periods, on demand, to help during peak demand periods when the power grid is under stress. Participants in load curtailment programs will receive significant payments for on demand load shedding. Let your Green initiatives extend beyond your building.

8. Space Utilization Management

LED retrofits provide a simple mechanism for generating measurable ROI for energy efficiency in a building. Lighting control system manufacturers have increasingly incorporated IoT occupancy sensors into LED fixtures to provide the most granular set of occupancy data in buildings. Certainly, this occupancy data can be used to turn off unneeded lights in a space.

More importantly, however, the occupancy data can be used to assess the true utilization of various rooms and spaces to determine whether the overall space should be redesigned or redistributed amongst building occupants. Sustainable building practices based on the re-commissioning of available space will ensure that efficient space utilization results. No good space should go to waste.

9. Virtual Building Automation System (BAS)

Many existing buildings do not have a BAS. Buildings that do have a BAS often face expensive upgrade paths to modernize its obsolete functionality. For example, a BAS may not have the benefit of occupancy data from the building, an array of temperature/humidity sensors scattered throughout a particular zone, peak demand program alerts, etc.

IoT solves this data problem. Retrofit IoT sensors capture additional data relevant to the HVAC controls. This IoT data would supplement existing data extracted from the BAS itself using industry standard protocols such as BACnet.

Virtual BASThe cloud aggregates the IoT data and BAS data into Big Data. An Artificial Intelligence (AI) Analytics Engine would then process the Big Data to produce automated intelligent controls. AI optimizations would then be fed back to the legacy BAS to supersede the HVAC programming. The cloud would transmit HVAC commands (e.g., changing of temperature setpoints) to the on-site BAS for execution. 

This architecture implements a type of virtual BAS that overlays a software application layer on top of an on-site BAS sub-system. The biggest benefit? Transforming your legacy on-site BAS into a cloud-based BAS that provides real-time analytics for building optimization. As compared to a BAS upgrade, a low-cost BAS retrofits provide the easiest path to a sustainable future.

10. Public Visibility and Engagement

Technology provides many paths to a sustainable future. One of the most under tapped resources for sustainable buildings is the engagement of building occupants. Every conservation program that can be envisioned, will be amplified when building occupants become partners in your Green initiatives.

Public visibility and engagement of sustainable initiatives can accelerate using real-time dashboards displayed in public areas (e.g., building lobby). Cloud-based visualizations that track the current status of sustainable initiatives and show the relevant impact on the environment (e.g., Green House Gases (GHG) saved) can lead to outsized results through engagement at a personal level.


These 10 retrofit methods all provide measurable value to existing buildings. Don’t consider their application independently. A technology bundle in platform solutions can deliver deeper efficiencies with a comprehensive approach that spans multiple retrofit methods.

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