You might be aware of some of the sustainability accreditations available in the marketplace but which one is right for your building? As part of our sustainability series, we’re unpacking the features, benefits and assessment criteria of each accreditation. 

Our latest article focuses on NABERS, a world leading environmental performance rating tool for commercial buildings. 

What is NABERS UK certification? 

The original NABERS (National Australian Built Environment Rating System) rating programme was established by the Australian government in 1998.  

NABERS ratings are used to assess and rate the energy efficiency and environmental impact of buildings. They consider factors such as energy and water consumption, waste management, and the quality of the indoor environment, to provide a more accurate understanding of how much energy an office uses in practice. 

The widespread use of NABERS energy ratings in Australia has been a major factor in improving the performance, cost of ownership and carbon emissions of both existing and new-build commercial office space. It is also strongly linked to increased market value and rental premiums compared to equivalent buildings without a NABERS rating.  

NABERS UK certification is an adaptation of the original programme. A simple, comparable, performance-based rating system, it is used to inform engineering design and introduce energy efficiency measures that help bolster the energy performance of office buildings, including during operational use.  

NABERS UK offers two products: 

• Energy for Offices: This system is for an existing building(s) and provides a NABERS UK energy rating based on its measured operational impact on the environment. 
• Design for Performance (DfP): This is a framework process implemented during the design stage. It ensures commitment by the developer or owner to embed energy targets within design, procurement, and delivery. A DfP agreement is required where the targeted NABERS UK energy rating is 4 stars or above, and ensures that the project delivers against its target design expectations. 

Why is NABERS UK popular? 

NABERS is unique in its focus on ensuring that the ultimate energy performance of a building in use is aligned with its design, procurement, and construction. 

For example, a building can be designed and modelled as being NABERS 5*, procured and built as 5*, and verified as 5* in use. 

As NABERS UK measures and rates the energy use of offices, it helps building owners to accurately track and communicate the energy performance of their building, and identify areas for savings and improvements.  

In addition:

1. The scheme uses a simple star rating to communicate the efficiency of a building to a non-technical audience.   
2. Detailed rules and quality assurance procedures ensure that ratings are reliable and repeatable between different assessors.
3. NABERS UK improves accountability through a separate assessment of the base building’s energy use, which is independent of the energy efficiency of a tenant’s energy needs. 
4. A rating demonstrates market leadership and enhances the reputation of a building, which in turn attracts premium tenants who want their offices to be energy efficient. 

 What are the benefits of NABERS UK certification?  

 Incorporating NABERS UK into the design of a building provides several benefits, including: 

• Reduction in environmental impact: energy efficiencies are optimised through advanced simulation modelling, testing the design against a range of expected operational scenarios. 
• Lower operational costs: particularly when compared with similar projects that are not registered for NABERS UK certification. 
• Journey to net zero: certification requirements support NABERS UK projects in achieving net zero operational carbon emissions. 
• Energy efficiency: helps deliver design intent for optimising energy use.   
• Third party verification: 12-months data post-occupancy is independently verified as part of the NABERS UK certification process. 

How are NABERS projects assessed? 

NABERS UK is administered by BRE, which is responsible for the day to day operations of the scheme. 

Early engagement with BRE is essential in establishing the type of assessment (i.e. for whole building, tenant or landlord areas).  

A NABERS UK assessment occurs post-practical completion and is based on actual consumption data of the building’s end users.  

All projects assessed for NABERS UK certification are required to meet the scheme’s assessment rules, which include: 

• The Net Lettable Area of the assessment must align with the RICS Net Internal Area measurement.   
• A correction adjustment for vacancies is applied as voids, so that only the occupied NLA is assessed in the rating.   
• Lift shafts, fire stairs, plant rooms, car parks, common areas, toilets, and foyers are excluded from the NLA measurement and classed as an overhead to the productive capacity of a building (i.e. as they are essentially non-productive spaces in terms of accommodating tenants and earning rent). 
• NABERS UK requires the customer to be involved from the outset of the project by initiating the pre-rating process with BRE Global, prior to the appointment of a NABERS UK assessor who will verify the rating. 
• A NABERS UK accredited assessor must be appointed to demonstrate whether the operational energy usage has met the design intent for energy. 
• The building’s performance over 12 contiguous months is supplied to the NABERS UK assessor, using data from utility bills, meter readings, and other sources. 
• There is a minimum threshold for post-occupancy to proceed with a NABERS UK assessment. 
• A minimum number of intensive energy simulation scenarios need to be modelled to inform the design development. 

How are NABERS projects scored? 

NABERS UK delivers a rating for buildings from one to six stars, with a scoring system that works in a similar way to the energy efficiency ratings for white goods such as fridges and washing machines. 

It provides a benchmark for progress, helping building owners to better understand their building’s performance when compared to other similar buildings. 

A six-star rating is classed as ‘world leading’ and demonstrates that significant efficiency measures have been incorporated to reduce consumption and, consequently, greenhouse gas emissions.  

Take a look at our NABERS UK *projects 

• Aspiring NABERS (rating level in design development): 5 St Philips Place, Birmingham  
• Target NABERS 5 star rating: 19 Cornwall St, Birmingham 

 * Both projects are currently in construction/preconstruction.