Launched in Australia and gaining traction in the UK, NABERS keeps buildings accountable for the energy they use every day. Amrita Dasgupta Shekhar, associate at Greengage, explains what you need to know about the certification.
What makes NABERS different to rating schemes like BREEAM?
The NABERS scheme rates the operational energy performance of buildings and is based on actual metered energy consumption data.
Although NABERS complements BREEAM, it is better suited to those looking for an energy performance rating to understand their progress towards energy reduction targets. This is an important distinction for organisations targeting net zero and looking for a way to qualify progress on energy reduction trajectories.
While BREEAM provides a single rating for the whole building, NABERS separates the base building ratings from the tenancy and whole building ratings. This gives both property owners and tenants actionable intelligence about energy use in the parts of the building they have direct control over, such as common areas like lifts or HVAC would be an owner’s concern while tenants would understand energy use in their own space.
Why should a building get NABERS certified?
Both investors and occupiers increasingly seek properties with strong energy performance credentials.
Here are just some of the benefits of a NABERS rating:
- Based on actual metered energy consumption as opposed to modelled data, NABERS provides an accurate assessment of the energy consumption of the building, thereby providing a tool to understand and improve energy performance
- Ratings are reliable, independently verified and trustworthy
- The ratings are easy to understand and communicate to the market via a simple star rating scale from one (poor) to six (market-leading)
- The NABERS UK scheme separates the base building ratings from the tenancy and whole building ratings, providing actionable intelligence to those in direct control of energy use
- NABERS ratings allows property owners to gain extra credits within GRESB and BREEAM, both new construction and in-use assessments.
- The scheme aligns with industry standards including:
- BCO Guide to Specification
- UKGBC Energy Use Intensity Targets for Net Zero Carbon Offices
- LETI Energy Use Intensity Targets for Offices
Is a six-star rating automatically good and one-star bad?
The purpose of NABERS is to drive improvement in energy performance over time. Since the ratings are valid only for a year, properties with high ratings are equally under pressure to maintain and improve ratings.
Low ratings should not become a barrier to properties undertaking ratings at scale as NABERS is meant to be a tool for improvement rather than just a badge for performance. Properties with lower ratings, while flagging poor performance, present an opportunity to develop and deliver an action plan for improvement.
How long is a NABERS rating valid – and why?
The NABERS rating is valid for 12 months and needs to be renewed on an annual basis. The annual review ensures that the rating accurately represents the building’s current operational energy performance at any given point in time.
This enables property owners to report performance to their stakeholders and supports building managers to plan improvements against targets.
What is the energy performance gap, and why is it a problem?
It’s the disparity between the estimated energy consumption at design stage and the actual energy consumption observed in new and retrofit buildings. According to several studies, actual energy consumption in new buildings can be up to 2.5-3x higher than predicted at design stage.
The underlying causes of the performance gap include uncertainties and underestimations introduced in building energy modelling, changes introduced during construction, poor commissioning and handover and poor occupant behaviour and energy management practices in operation. This is well documented by the likes of Royal Institute of British Architects (RIBA), Chartered Institute of Building Service Engineers (CIBSE) and Building Service Research and Information Association (BSRIA), among others.
The performance gap is a key barrier to realising carbon reduction targets. Specifically, within the UK where construction practices and building energy policies such as MEES use estimated energy consumption data as a route to compliance, the performance gap causes a disconnect between the regulatory framework and the actual performance of buildings.
Could NABERS become mandatory?
There is no indication from the government that NABERS will be mandated in the UK.
In 2021, BEIS published a consultation on introducing performance-based policy framework in large commercial and industrial buildings, with annual ratings and mandatory disclosure as a first step. The consultation covered NABERS, acknowledging its success and strengths, and discusses the attributes of NABERS that would be important to reflect within a national scheme.
However, the government is yet to publish the results of the consultation and its approach to rating and disclosing operational performance.
How does a building get NABERS-certified?
To begin the process, contact a licensed NABERS assessor. The assessor will review the property to evaluate if all information is available for an assessment. They will then liaise with your team to gather the necessary information, carry out the assessment and lodge a rating with BRE.
Amrita Dasgupta Shekhar is an associate at sustainability consultancy Greengage.
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