Grosvenor achieves the UK's first NABERS Base Building Energy Rating

03 July 2024
Topic: Energy/Carbon
Type: Case Studies
Member: Grosvenor
Grosvenor Building

Grosvenor achieves the UK's first NABERS Base Building Energy Rating

03 July 2024
Topic: Energy/Carbon
Type: Case Studies
Member: Grosvenor

Grosvenor's Toronto Square, Leeds, has earned a NABERS (National Australian Built Environment Rating System) UK Base Building Energy Rating of 4.5*, marking the first occasion in the UK where an existing office building has received such recognition. This is a landmark achievement for Grosvenor, one that establishes them as leaders within the industry and signals the start of an exciting chapter in which Grosvenor aims to achieve further NABERS UK ratings across their portfolio. NABERS accredited office buildings are making significant strides towards achieving Net Zero goals with Grosvenor benefitting from enhanced transparency and occupier engagement as key methods to guide future decision making.

Key Facts

  • Awarded the first NABERS UK Base Building Energy Rating
  • Grosvenor achieved 4.5* rating (out of 6)
  • Increased focus on energy efficiency as part of NABERS UK Base Building Energy Rating process helped save 5-7% in annual energy costs
  • Effective engagement resulted in occupiers increased interest to achieve NABERS Tenancy Energy Rating for their own areas
  • Toronto Square also achieved BREEAM Very Good rating
  • Grade A offices

The Situation

The NABERS scheme was first developed in New South Wales, Australia, in 1998. NABERS enables building owners to accurately measure, verify and communicate the energy performance of their buildings, demonstrating that their buildings are on a Net Zero carbon pathway. The NABERS scheme has already helped commercial offices save an average of 30-40% on their energy over a 10 year period. Since 1998, NABERS has expanded its reach internationally and now includes rating schemes for not only offices but also a range of building types including, hotels, schools, warehouses and apartment buildings.

In 2019, The NABERS UK Energy for Office Scheme entered the UK market with BBP acting as an ambassador for the scheme. The scheme bridges the gap between the design and performance in-use of offices, measuring and verifying the actual energy use of operational offices which enables building owners to measure, improve and communicate energy performance accurately.

Toronto Square, Leeds, is an 8000m2 office building owned by Grosvenor and was the first property in the UK to achieve an impressive NABERS UK Base Building Energy Rating of 4.5*. This has not only raised the profile of Grosvenor across UK real estate but also the reputation of Toronto Square amongst current and prospective occupiers. Grosvenor has an ambitious environmental strategy to achieve Net Zero by 2040 through a 90% reduction of carbon emissions and are striving for NABERS UK rating above 4.5* across all office buildings over 1000m2 by the end of 2025.


Engaging with occupiers was a crucial first step to gather accurate information for submission to NABERS. Grosvenor engaged early with occupiers on the benefits of NABERS UK and the opportunity for their businesses to support and input into the overall process. This engagement was conducted in collaboration with CBRE – the Managing Agent.

While sustainability was a top priority for many occupiers, there was uncertainty about the data required of them. Working closely with CBRE, Grosvenor were intentional about educating and engaging each occupier through one-on-one meetings to boost confidence and awareness.

The following data and information (not exhaustive) was collated on site to achieve the rating:

  • Asset data including, detailed floor plates, third party Survey and/or drawings (part of lease document) conforming to measurement standard as per RICS Code of Measuring Practice (2015), and metering and electrical schematics/photographs.
  • Energy data including, generator fuel used in last year, electricity and gas bills for most recent 12 months, metering validation certificates for each non-utility meter for electricity and gas meters, and copies of Air Handling request data.
  • Lease/occupier data including, lease agreements for each tenant with hours of operation, Office NIA (Net Internal Area) for each tenant occupied space, non-utility metering data (electricity and gas) for tenant usage for last 12 months, and location of tenant meters.

The intensive process to achieve NABERS requires effective collaboration across several stakeholders. This has enabled Grosvenor to identify of key areas of improvement for longer-term design and retrofit interventions, as well as operational optimisation of both landlord-controlled building assets, and occupier-led interventions.


As NABERS UK focuses on everyday use of carbon and energy, it has provided Grosvenor with a clear and positive benchmark for improvement at Toronto Square. Independently verified performance will improve the overall accuracy of sustainability reporting data and enhance brand reputation and integrity.

Through the collection of the data required for submission and engagement with occupiers, Grosvenor has successfully identified quick wins and long-term opportunities that will ensure energy usage decreases across Toronto Square. For example, an understanding of core office hours and office use has enabled optimisation of the energy plant.

Other current and future interventions to reduce energy use include installing area heat and light sensors, the addition of water timers and ongoing projects to replace HVAC on all floors to more efficient systems. Occupiers have also been incentivised to save energy themselves with various occupiers opting to install LED light bulbs and motion sensors as well as reducing thermostat temperatures and switching off appliances.

A key benefit of NABERS UK for Grosvenor has been the number of occupiers who have voiced their desire to achieve NABERS ratings for their own area (NABERS Tenancy Energy Rating). If occupiers pursue this rating it will support Grosvenor’s goal to become Net Zero by 2040 by tackling emissions associated with the use of occupier spaces that are outside of Grosvenor’s direct control.

Grosvenor are now looking at M&E alongside a Building Management System replacement to allow analysis of equipment-level consumption to identify further ways to reduce energy usage. This will empower building managers and occupiers to better understand the impact of practical interventions, so that the building meets occupier needs without wasting energy.

Challenges and Achievements

The NABERS process has been extremely worthwhile in raising awareness of operational inefficiencies, empowering the team to identify practical steps to drive down carbon emissions. Importantly, it has proved improvements can be made very quickly, such as fixing faulty equipment or re-calibrating it to match working hours, while enabling longer-term planning to address building design and retrofit considerations.

Occupiers were very receptive to the process and were keen to understand how they can contribute and drive down consumption in their own areas. However, a challenge remains in achieving their own NABERS rating due to the level of building-specific expertise required to effectively gather the data required and then act on the identified interventions. Grosvenor want to further investigate these barriers to entry for occupiers so that they can better support them in making and accrediting their operational performance.

Overall, the process has provided an excellent opportunity to follow a data-led approach to collaboration with occupiers on the shared goal of operating net zero buildings. As Grosvenor continue to roll out NABERS assessments across large offices, they seek to lead the way on increasing transparency of operational performance, encouraging occupiers to demand clear and practical information to enable emissions reductions. 


Grosvenor is an international organisation whose activities span urban property, food and agtech, rural estate management and support for philanthropic initiatives. We are a values-led business which represents the Grosvenor family and share a common purpose - to deliver lasting commercial, social and environmental benefit - addressing today’s needs while taking responsibility for those of future generations. 

With a track record of over 340 years, we work to improve urban property and places in many of the world’s leading cities, promoting sustainability within the built environment and enhancing the wellbeing of customers and communities.


CBRE Global Investors is one of the largest real estate investment management firms, with over £10 billion AUM in the UK alone. Our services include management of primary funds, investments in other property investment vehicles and assets for regional open core funds. 


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