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1 Cal Reaches for Best in Class in Green Building

Rising Realty Partners aimed to create a best-in-class sustainable, energy-efficient and cost-effective high-rise at its flagship building in downtown Los Angeles

glass building against the sky

Collaborating with UL Solutions allowed 1 Cal to pursue certifications and verifications that would enhance its reputation as a sustainable building. “Buildings are responsible for such a large part of energy use, and as a high rise totaling over a million square feet, we take that responsibility very seriously,” Desiderio emphasized. “We aim to do everything we can to make a positive impact. 1 Cal is a building that focuses on creating a more sustainable future for our employees, tenants and the community as a whole.” 

To that end, the UL Solutions team also helped 1 Cal pursue the UL Verified Healthy Building Mark, ENERGY STAR certification and Ventilation Assessments for Indoor Air Quality. 

“Rising has always been a sustainability-focused company,” Desiderio added. “Our team is always looking for ways to set ourselves apart. We’re constantly investing in our sustainability certifications and education for our staff and tenants, so these certifications and verifications are validation that we are accomplishing what we’ve set out to do.”

“At 1 Cal, we’re always trying to be a trailblazer that sets the standard for other buildings, so it made sense to get the LEED Platinum Renewal Certification. The goal is to progressively get better and better, so we decided to pursue LEED Zero Energy and LEED Zero Carbon as well.” 

- Nina Desiderio, General Manager at 1 Cal Plaza. 

Collaborating to reach new heights

The UL Solutions team coordinated 1 Cal’s LEED Operations and Maintenance (O+M) Platinum Renewal Certification, which awards points based on how sustainably the building is being operated and maintained. The LEED O+M Platinum Renewal Certification served as the main certification that worked in concert with other certifications and verifications that 1 Cal pursued, with many green building activities counting toward multiple certifications. By becoming Net Zero Energy and ENERGY STAR certified, 1 Cal received points toward its LEED O+M certification. Furthermore, by receiving the UL Verified Healthy Building Mark, 1 Cal also received points toward its LEED O+M certification for indoor environmental quality from air quality assessments that the UL Solutions performed. 

In order to achieve the LEED O+M certification, UL Solutions had to complete documentation that records how efficient water usage is, carbon emissions associated with transportation, energy efficiency, indoor air quality, waste management, recycling, green cleaning supplies use and more.

The collaboration allowed UL Solutions and 1 Cal to make strides in sustainability together. 1 Cal became the first UL Solutions customer to achieve LEED Certified Net Zero Energy and Net Zero Carbon. As a result, 1 Cal became the second high rise in Los Angeles to achieve the Net Zero Energy certification and the first to achieve the Net Zero Carbon certification*.

*Source: 1 Cal Plaza Achieves Prestigious LEED Zero Carbon Certification, Demonstrating Excellence in Net Zero Performance - Rising Realty Partners (

Communication is vital to certification success 

The key to achieving so many certifications and verifications simultaneously was the UL Solutions team’s excellent communication with 1 Cal. “The customer service was always top-notch,” said Desiderio. “If myself or a tenant had a question about testing or monitoring, our UL Solutions representative was always very knowledgeable and could coordinate with the different departments and keep me up-to-date regularly.”

1 Cal pursued the UL Verified Healthy Building Mark to give building occupants confidence in the indoor air quality, which was important to tenant peace of mind during the pandemic. “Being in property management, first and foremost, you want to ensure that your tenants are safe, and their wellbeing is prioritized,” said Desiderio. “Having the UL Verified Healthy Building Mark helps tenants to feel more comfortable knowing that [there is] testing and monitoring [is] being done regularly.”

Desiderio considered other wellness certifications and verifications before choosing the UL Verified Healthy Building Mark. “What really set the UL Verified Healthy Building Mark apart was its comprehensive nature,” Desiderio said. “It was everything I was looking for in a verification mark to reassure my tenants that the air they’re breathing at 1 Cal is within healthy standards.”

Having UL Solutions to help manage the LEED certification process is crucial, according to Desiderio. “If I had to do this all on my own, without the assistance of UL Solutions, I truly don’t know how that would happen. UL Solutions was instrumental in guiding us through this entire process.”

“Having a central point of contact for our clients is how we ensure every question gets answered and our clients always have all the latest updated information.”

- Gabriela De Vasconcellos, Sustainability Consultant, Asset & Sustainability Performance at UL Solutions

The final scorecard: Achieving LEED O+M and more

UL Solutions’ services for 1 Cal Plaza included:

LEED O+M Certification – Platinum (Renewal) 

UL Solutions LEED advisory team supported 1 Cal Plaza in pursuing LEED  Existing Buildings Operations and Maintenance (O+M) v4 Platinum certification. This rating system evaluates how sustainably 1 Cal Plaza is maintained and operated by assessing its carbon emissions from building occupants’ transportation, water and energy use, waste recycling rates, sustainable procurement, and other indoor environmental parameters that impact human health and well-being. 1 Cal Plaza achieved Platinum Certification in 2022.

LEED Net Zero Energy Certification

LEED Zero Energy recognizes buildings that offset source energy use with renewable energy. This certification utilizes the ENERGY STAR program to collect performance data and contribute towards the LEED O+M certification with points under the Energy and Atmosphere category.

LEED Zero Carbon

1 Cal Plaza obtained the Zero Carbon certification in 2022. This program recognizes buildings operating with net zero carbon emissions over the course of a year, including not only energy use but also emissions associated with occupant transportation.

UL Verified Healthy Building Mark

This is a holistic look at a building’s indoor environment, assessing indoor air quality and water quality as well as building cleanliness, lighting and acoustics. 1 Cal Plaza achieved the UL Verified Healthy Building Mark for Indoor Environment, which contributed to LEED EBOM v4 Platinum certification, contributing to points under the Indoor Environmental Quality category.

ENERGY STAR Certification

Benchmarking a building’s water and energy usage offers a view of how a building is performing versus its peers in the same category, size and location. 1 Cal Plaza receives recognition through the program every year, and in addition to an ENERGY STAR certification, the program also contributed 13 points under Energy & Atmosphere Optimize Energy Performance for the LEED EBOM v4 Platinum certification.

Ventilation Assessment for Indoor Air Quality

The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard 62.1 is a widely accepted standard to verify the amount of ventilation air delivered in commercial buildings by HVAC systems is sufficient to support acceptable indoor air quality. 1 Cal is using the data to ensure adequate ventilation in all areas of the building and maximize energy savings opportunities through economization strategies.

Certifications and verifications provide peace of mind

Desiderio is proud 1 Cal Plaza has achieved each one of the certifications and verifications. “Tenants have reached out to us to verify that we have the certifications and verifications because they want to highlight the indoor air quality when asking employees to return to the building after the pandemic,” said Desiderio. “Being armed with this information helps people feel better about coming back to the building instead of working remotely.”

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1 Cal Reaches for Best in Class in Green Building (Case Study)

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