In Sydney, a prominent commercial office building was being inspected for its latest NABERS Indoor Environment (IE) score. As part of its commitment to sustainability and excellence, the building underwent the voluntary assessment, aiming to maintain its high standards in indoor environment quality, having already held a 6 Star rating.
During the assessment, a built environment assessor identified a critical issue. Three sensors on Level 7 were malfunctioning, showing stagnant data below 21°C between October and December 2022. This sensor failure risked the building's coveted NABERS IE rating, threatening to drop it from an exceptional 6 stars to a 5.5 star rating. This decline was significant, as the building is a key asset in a large REIT's portfolio renowned for its high rankings on the NABERS Sustainable Portfolios Index.
The root of this problem lay in the previous management's failure to address the sensor issue, despite being alerted via PEAK Alerts. This oversight resulted in the building management system (BMS) lacking reliable zone temperature data, critical for the NABERS assessment.
Fortunately, CIM's PEAK Platform had been monitoring zone temperature data at the property since November 2021. The Facilities Manager swiftly stepped in to provide the assessors with this alternative dataset from the functional sensors on Level 7, ensuring the accuracy and integrity of the NABERS assessment.
Thanks to the availability of data and continuous monitoring enabled through the PEAK Platform, the assessors were able to use the alternative sensor data to validate the building's thermal comfort scores. This intervention directly led to the building retaining its prestigious 6-star NABERS Indoor Environment rating, a testament to our software's capabilities in safeguarding sustainability standards.
- Reputational maintenance: The building's top rating contributes to the REIT's standing on the NABERS Sustainable Portfolios Index, reinforcing its reputation for prioritising the tenant experience.
- Criticality of data and sensors: This scenario underscores the importance of reliable data and functional sensors in achieving and maintaining high NABERS IE scores. In this case, the PEAK Platform added real value through its continuous intelligent monitoring, comprehensive data coverage and ease of access to said data.
- Wider industry relevance: The NABERS IE rating is increasingly influential in the real estate sector, impacting leasing requirements, attracting quality tenants, and even affecting sustainability-linked loans. Our intervention demonstrates how essential such ratings are for top property owners and the growing tenant demand for independent validation of a building's indoor environment.
Understanding how NABERS IE is calculated
The NABERS IE (Indoor Environment) rating system is a comprehensive benchmarking tool designed to assess the indoor environment quality of buildings, giving an office space or whole building a rating from one to six stars. It is based on three critical parameters: thermal comfort, air quality, and acoustic comfort. Each parameter contributes significantly to the overall score, highlighting the necessity for continuous and accurate data collection.
- Thermal Comfort (40% weight): This aspect is paramount in the NABERS IE rating system. It requires 12 months of continuous data from temperature sensors, supplemented by site visit spot measurements. Thermal comfort is a major determinant of the overall NABERS IE score, emphasizing the need for consistent and reliable temperature monitoring within the building.
- Air Quality (40%): The assessment of air quality involves on-site measurements of particulate matter, such as pollen and dust. This parameter is equally weighted with thermal comfort, underscoring its importance in evaluating the overall indoor environment quality.
- Acoustic Comfort (20%): This parameter is assessed through on-site measurements of sound levels in key areas of the building. While it has a lower weightage compared to thermal comfort and air quality, it remains a vital component of the overall NABERS IE rating.
The importance of sample size and data integrity
- Sample Size: Up to 30 critical sensors are nominated by an independent assessor for each building. This ensures a comprehensive and representative sample of the building's environment.
- Data Requirement: Each nominated sensor must provide 12 months of continuous hourly temperature data. This rigorous data collection process is crucial for an accurate assessment of thermal comfort.
- Minimum Data Threshold: At least 90% of the annual sample data is required for each sensor. This high threshold ensures the reliability and completeness of the data used in the rating.
Scoring scale and risk management
- Scoring Scale: The NABERS IE rating ranges from 0% to 100%, with an average score being around 94%. The score is calculated as the percentage of total hourly sensor sample data that falls within the optimal temperature range (21.0°C to 24.9°C) during typical working hours (9am to 5pm on weekdays).
- Risk of Incomplete Data: If a sensor's annual data falls below the 90% threshold, it is treated as a 0% score. This emphasizes the risk associated with unreliable or broken sensors and the importance of their timely maintenance and replacement.
Our PEAK Platform excels in addressing these challenges. By providing reliable, continuous data monitoring, it enables buildings to accurately measure and improve their NABERS IE scores. This capability not only enhances the indoor environment quality but also contributes to the building's sustainability and tenant satisfaction.